text: // SPDX-License-Identifier: GPL-2.0
  /*
   * Completely Fair Scheduling (CFS) Class (SCHED_NORMAL/SCHED_BATCH)
   *
   *  Copyright (C) 2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
   *
   *  Interactivity improvements by Mike Galbraith
   *  (C) 2007 Mike Galbraith <efault@gmx.de>
   *
   *  Various enhancements by Dmitry Adamushko.
   *  (C) 2007 Dmitry Adamushko <dmitry.adamushko@gmail.com>
   *
   *  Group scheduling enhancements by Srivatsa Vaddagiri
   *  Copyright IBM Corporation, 2007
   *  Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
   *
   *  Scaled math optimizations by Thomas Gleixner
   *  Copyright (C) 2007, Thomas Gleixner <tglx@linutronix.de>
   *
   *  Adaptive scheduling granularity, math enhancements by Peter Zijlstra
   *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra
   */
  
  #include <linux/sched/mm.h>
  #include <linux/sched/topology.h>
  
  #include <linux/latencytop.h>
  #include <linux/cpumask.h>
  #include <linux/cpuidle.h>
  #include <linux/slab.h>
  #include <linux/profile.h>
  #include <linux/interrupt.h>
  #include <linux/mempolicy.h>
  #include <linux/migrate.h>
  #include <linux/task_work.h>
  
  #include <linux/cpufreq.h>
  #include <linux/list_sort.h>
  
  #include <trace/events/sched.h>
  
  #include "sched.h"
  #include "tune.h"
  #include "walt.h"
  
  #ifdef CONFIG_HW_VIP_THREAD
  #include <chipset_common/hwcfs/hwcfs_common.h>
  #endif
  
  /*
   * Targeted preemption latency for CPU-bound tasks:
   *
   * NOTE: this latency value is not the same as the concept of
   * 'timeslice length' - timeslices in CFS are of variable length
   * and have no persistent notion like in traditional, time-slice
   * based scheduling concepts.
   *
   * (to see the precise effective timeslice length of your workload,
   *  run vmstat and monitor the context-switches (cs) field)
   *
   * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
   */
  unsigned int sysctl_sched_latency			= 6000000ULL;
  unsigned int normalized_sysctl_sched_latency		= 6000000ULL;
  
  /*
   * Enable/disable honoring sync flag in energy-aware wakeups.
   */
  unsigned int sysctl_sched_sync_hint_enable = 1;
  /*
   * Enable/disable using cstate knowledge in idle sibling selection
   */
  unsigned int sysctl_sched_cstate_aware = 1;
  #ifdef CONFIG_HISI_EAS_SCHED
  int boot_boost = 1;
  unsigned int sd_capacity_margin = 1280;
  unsigned int up_migration_util_filter = 25;
  int global_boost_enable = 0;
  unsigned int task_boost_limit = SCHED_CAPACITY_SCALE; /* default no limit */
  #endif
  
  /*
   * The initial- and re-scaling of tunables is configurable
   *
   * Options are:
   *
   *   SCHED_TUNABLESCALING_NONE - unscaled, always *1
   *   SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
   *   SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
   *
   * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
   */
  enum sched_tunable_scaling sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG;
  
  /*
   * Minimal preemption granularity for CPU-bound tasks:
   *
   * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
   */
  unsigned int sysctl_sched_min_granularity		= 750000ULL;
  unsigned int normalized_sysctl_sched_min_granularity	= 750000ULL;
  
  /*
   * This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity
   */
  static unsigned int sched_nr_latency = 8;
  
  /*
   * After fork, child runs first. If set to 0 (default) then
   * parent will (try to) run first.
   */
  unsigned int sysctl_sched_child_runs_first __read_mostly;
  
  /*
   * SCHED_OTHER wake-up granularity.
   *
   * This option delays the preemption effects of decoupled workloads
   * and reduces their over-scheduling. Synchronous workloads will still
   * have immediate wakeup/sleep latencies.
   *
   * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
   */
  unsigned int sysctl_sched_wakeup_granularity		= 1000000UL;
  unsigned int normalized_sysctl_sched_wakeup_granularity	= 1000000UL;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  const_debug unsigned int sysctl_sched_migration_cost = 0UL;
  #else
  const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
  #endif
  
  #ifdef CONFIG_SCHED_WALT
  #ifdef CONFIG_SCHED_HISI_USE_WALT
  __read_mostly unsigned int sysctl_sched_use_walt_cpu_util = 1;
  __read_mostly unsigned int sysctl_sched_use_walt_task_util = 1;
  #else
  __read_mostly unsigned int sysctl_sched_use_walt_cpu_util = 0;
  __read_mostly unsigned int sysctl_sched_use_walt_task_util = 0;
  #endif /* CONFIG_SCHED_HISI_USE_WALT */
  __read_mostly unsigned int sysctl_sched_use_walt_cpu_util_freq = 1;
  #ifdef CONFIG_HISI_EAS_SCHED
  #ifdef CONFIG_SCHED_HISI_DEPRECATED
  __read_mostly unsigned int sysctl_sched_walt_cpu_high_irqload =
      (NSEC_PER_SEC / CONFIG_HZ);
  #else
  __read_mostly unsigned int sysctl_sched_walt_cpu_high_irqload =
      (2 * NSEC_PER_SEC / CONFIG_HZ);
  #endif
  __read_mostly unsigned int sysctl_sched_walt_cpu_overload_irqload =
      (3 * NSEC_PER_SEC / CONFIG_HZ);
  #else
  __read_mostly unsigned int sysctl_sched_walt_cpu_high_irqload =
      (10 * NSEC_PER_MSEC);
  #endif /* CONFIG_HISI_EAS_SCHED */
  #endif
  
  #ifdef CONFIG_SMP
  /*
   * For asym packing, by default the lower numbered cpu has higher priority.
   */
  int __weak arch_asym_cpu_priority(int cpu)
  {
  	return -cpu;
  }
  #endif
  
  #ifdef CONFIG_CFS_BANDWIDTH
  /*
   * Amount of runtime to allocate from global (tg) to local (per-cfs_rq) pool
   * each time a cfs_rq requests quota.
   *
   * Note: in the case that the slice exceeds the runtime remaining (either due
   * to consumption or the quota being specified to be smaller than the slice)
   * we will always only issue the remaining available time.
   *
   * (default: 5 msec, units: microseconds)
   */
  unsigned int sysctl_sched_cfs_bandwidth_slice		= 5000UL;
  #endif
  
  /*
   * The margin used when comparing utilization with CPU capacity:
   * util * margin < capacity * 1024
   *
   * (default: ~20%)
   */
  unsigned int capacity_margin				= 1280;
  
  #ifdef CONFIG_HISI_MULTI_MARGIN
  static inline unsigned int hisi_capacity_margin(int cpu)
  {
  	return cpu_rq(cpu)->cluster->capacity_margin;
  }
  
  static inline unsigned int hisi_sd_capacity_margin(int cpu)
  {
  	return cpu_rq(cpu)->cluster->sd_capacity_margin;
  }
  #else /* CONFIG_HISI_MULTI_MARGIN */
  static inline unsigned int hisi_capacity_margin(int cpu)
  {
  	return capacity_margin;
  }
  
  #ifdef CONFIG_HISI_EAS_SCHED
  static inline unsigned int hisi_sd_capacity_margin(int cpu)
  {
  	return sd_capacity_margin;
  }
  #else
  static inline unsigned int hisi_sd_capacity_margin(int cpu)
  {
  	return capacity_margin;
  }
  #endif
  #endif /* CONFIG_HISI_MULTI_MARGIN */
  
  #ifdef CONFIG_HISI_EAS_SCHED
  
  struct list_head cluster_head;
  int num_clusters;
  
  struct sched_cluster init_cluster = {
  	.list			=	LIST_HEAD_INIT(init_cluster.list),
  	.id			=	0,
  	.max_possible_capacity	=	1024,
  	.cur_freq		=	1,
  	.max_freq		=	1,
  	.min_freq		=	1,
  	.capacity_margin	=	1280,
  	.sd_capacity_margin	=	1280,
  };
  
  static void assign_cluster_ids(struct list_head *head)
  {
  	struct sched_cluster *cluster;
  	int pos = 0;
  
  	list_for_each_entry(cluster, head, list) {
  		cluster->id = pos++;
  	}
  }
  
  static void
  move_list(struct list_head *dst, struct list_head *src, bool sync_rcu)
  {
  	struct list_head *first, *last;
  
  	first = src->next;
  	last = src->prev;
  
  	if (sync_rcu) {
  		INIT_LIST_HEAD_RCU(src);
  		synchronize_rcu();
  	}
  
  	first->prev = dst;
  	dst->prev = last;
  	last->next = dst;
  
  	/* Ensure list sanity before making the head visible to all CPUs. */
  	smp_mb();
  	dst->next = first;
  }
  
  static void
  insert_cluster(struct sched_cluster *cluster, struct list_head *head)
  {
  	struct sched_cluster *tmp;
  	struct list_head *iter = head;
  
  	list_for_each_entry(tmp, head, list) {
  		/*
  		 * FIXME:
  		 * Because sched_init is called before cpufreq_init, we
  		 * got wrong max_possible_capacity here in kernel 4.14. We
  		 * should sort clusters later in a cpufreq notify.
  		 * Temporarily use cpu id here.
  		 */
  		// if (cluster->max_possible_capacity < tmp->max_possible_capacity)
  		// 	break;
  		if (cpumask_first(&cluster->cpus) < cpumask_first(&tmp->cpus))
  			break;
  		iter = &tmp->list;
  	}
  
  	list_add(&cluster->list, iter);
  }
  
  static struct sched_cluster *alloc_new_cluster(const struct cpumask *cpus)
  {
  	struct sched_cluster *cluster = NULL;
  
  	cluster = kzalloc(sizeof(struct sched_cluster), GFP_ATOMIC);
  	if (!cluster) {
  		pr_warn("Cluster allocation failed. Possible bad scheduling\n");
  		return NULL;
  	}
  
  	INIT_LIST_HEAD(&cluster->list);
  	cluster->max_possible_capacity	=	arch_scale_cpu_capacity(NULL, cpumask_first(cpus));
  	cluster->cur_freq		=	1;
  	cluster->max_freq		=	1;
  	cluster->min_freq		=	1;
  	cluster->freq_init_done		=	false;
  	cluster->capacity_margin	=	capacity_margin;
  	cluster->sd_capacity_margin	=	sd_capacity_margin;
  
  	cluster->cpus = *cpus;
  
  	return cluster;
  }
  
  static void add_cluster(const struct cpumask *cpus, struct list_head *head)
  {
  	struct sched_cluster *cluster = alloc_new_cluster(cpus);
  	int i;
  
  	if (!cluster)
  		return;
  
  	for_each_cpu(i, cpus)
  		cpu_rq(i)->cluster = cluster;
  
  	insert_cluster(cluster, head);
  	num_clusters++;
  }
  
  void update_cluster_topology(void)
  {
  	struct cpumask cpus = *cpu_possible_mask;
  	const struct cpumask *cluster_cpus;
  	struct list_head new_head;
  	int i;
  
  	INIT_LIST_HEAD(&new_head);
  
  	for_each_cpu(i, &cpus) {
  		cluster_cpus = cpu_coregroup_mask(i);
  		cpumask_andnot(&cpus, &cpus, cluster_cpus);
  		add_cluster(cluster_cpus, &new_head);
  	}
  
  	assign_cluster_ids(&new_head);
  
  	/*
  	 * Ensure cluster ids are visible to all CPUs before making
  	 * cluster_head visible.
  	 */
  	move_list(&cluster_head, &new_head, false);
  }
  
  void init_clusters(void)
  {
  	init_cluster.cpus = *cpu_possible_mask;
  	INIT_LIST_HEAD(&cluster_head);
  }
  
  #endif /* CONFIG_HISI_EAS_SCHED */
  
  static inline void update_load_add(struct load_weight *lw, unsigned long inc)
  {
  	lw->weight += inc;
  	lw->inv_weight = 0;
  }
  
  static inline void update_load_sub(struct load_weight *lw, unsigned long dec)
  {
  	lw->weight -= dec;
  	lw->inv_weight = 0;
  }
  
  static inline void update_load_set(struct load_weight *lw, unsigned long w)
  {
  	lw->weight = w;
  	lw->inv_weight = 0;
  }
  
  #ifdef CONFIG_HISI_CORE_CTRL
  static void inc_cfs_nr_heavy_running(struct rq *update_rq,
  				     struct task_struct *p);
  static void dec_cfs_nr_heavy_running(struct rq *update_rq,
  				     struct task_struct *p);
  #endif
  
  /*
   * Increase the granularity value when there are more CPUs,
   * because with more CPUs the 'effective latency' as visible
   * to users decreases. But the relationship is not linear,
   * so pick a second-best guess by going with the log2 of the
   * number of CPUs.
   *
   * This idea comes from the SD scheduler of Con Kolivas:
   */
  static unsigned int get_update_sysctl_factor(void)
  {
  	unsigned int cpus = min_t(unsigned int, num_online_cpus(), 8);
  	unsigned int factor;
  
  	switch (sysctl_sched_tunable_scaling) {
  	case SCHED_TUNABLESCALING_NONE:
  		factor = 1;
  		break;
  	case SCHED_TUNABLESCALING_LINEAR:
  		factor = cpus;
  		break;
  	case SCHED_TUNABLESCALING_LOG:
  	default:
  		factor = 1 + ilog2(cpus);
  		break;
  	}
  
  	return factor;
  }
  
  static void update_sysctl(void)
  {
  	unsigned int factor = get_update_sysctl_factor();
  
  #define SET_SYSCTL(name) \
  	(sysctl_##name = (factor) * normalized_sysctl_##name)
  	SET_SYSCTL(sched_min_granularity);
  	SET_SYSCTL(sched_latency);
  	SET_SYSCTL(sched_wakeup_granularity);
  #undef SET_SYSCTL
  }
  
  void sched_init_granularity(void)
  {
  	update_sysctl();
  }
  
  #define WMULT_CONST	(~0U)
  #define WMULT_SHIFT	32
  
  static void __update_inv_weight(struct load_weight *lw)
  {
  	unsigned long w;
  
  	if (likely(lw->inv_weight))
  		return;
  
  	w = scale_load_down(lw->weight);
  
  	if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST))
  		lw->inv_weight = 1;
  	else if (unlikely(!w))
  		lw->inv_weight = WMULT_CONST;
  	else
  		lw->inv_weight = WMULT_CONST / w;
  }
  
  /*
   * delta_exec * weight / lw.weight
   *   OR
   * (delta_exec * (weight * lw->inv_weight)) >> WMULT_SHIFT
   *
   * Either weight := NICE_0_LOAD and lw \e sched_prio_to_wmult[], in which case
   * we're guaranteed shift stays positive because inv_weight is guaranteed to
   * fit 32 bits, and NICE_0_LOAD gives another 10 bits; therefore shift >= 22.
   *
   * Or, weight =< lw.weight (because lw.weight is the runqueue weight), thus
   * weight/lw.weight <= 1, and therefore our shift will also be positive.
   */
  static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight *lw)
  {
  	u64 fact = scale_load_down(weight);
  	int shift = WMULT_SHIFT;
  
  	__update_inv_weight(lw);
  
  	if (unlikely(fact >> 32)) {
  		while (fact >> 32) {
  			fact >>= 1;
  			shift--;
  		}
  	}
  
  	/* hint to use a 32x32->64 mul */
  	fact = (u64)(u32)fact * lw->inv_weight;
  
  	while (fact >> 32) {
  		fact >>= 1;
  		shift--;
  	}
  
  	return mul_u64_u32_shr(delta_exec, fact, shift);
  }
  
  
  const struct sched_class fair_sched_class;
  
  /**************************************************************
   * CFS operations on generic schedulable entities:
   */
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  
  /* cpu runqueue to which this cfs_rq is attached */
  static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
  {
  	return cfs_rq->rq;
  }
  
  /* An entity is a task if it doesn't "own" a runqueue */
  #define entity_is_task(se)	(!se->my_q)
  
  static inline struct task_struct *task_of(struct sched_entity *se)
  {
  	SCHED_WARN_ON(!entity_is_task(se));
  	return container_of(se, struct task_struct, se);
  }
  
  /* Walk up scheduling entities hierarchy */
  #define for_each_sched_entity(se) \
  		for (; se; se = se->parent)
  
  static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
  {
  	return p->se.cfs_rq;
  }
  
  /* runqueue on which this entity is (to be) queued */
  static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
  {
  	return se->cfs_rq;
  }
  
  /* runqueue "owned" by this group */
  static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
  {
  	return grp->my_q;
  }
  
  static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq)
  {
  	if (!cfs_rq->on_list) {
  		struct rq *rq = rq_of(cfs_rq);
  		int cpu = cpu_of(rq);
  		/*
  		 * Ensure we either appear before our parent (if already
  		 * enqueued) or force our parent to appear after us when it is
  		 * enqueued. The fact that we always enqueue bottom-up
  		 * reduces this to two cases and a special case for the root
  		 * cfs_rq. Furthermore, it also means that we will always reset
  		 * tmp_alone_branch either when the branch is connected
  		 * to a tree or when we reach the beg of the tree
  		 */
  		if (cfs_rq->tg->parent &&
  		    cfs_rq->tg->parent->cfs_rq[cpu]->on_list) {
  			/*
  			 * If parent is already on the list, we add the child
  			 * just before. Thanks to circular linked property of
  			 * the list, this means to put the child at the tail
  			 * of the list that starts by parent.
  			 */
  			list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list,
  				&(cfs_rq->tg->parent->cfs_rq[cpu]->leaf_cfs_rq_list));
  			/*
  			 * The branch is now connected to its tree so we can
  			 * reset tmp_alone_branch to the beginning of the
  			 * list.
  			 */
  			rq->tmp_alone_branch = &rq->leaf_cfs_rq_list;
  		} else if (!cfs_rq->tg->parent) {
  			/*
  			 * cfs rq without parent should be put
  			 * at the tail of the list.
  			 */
  			list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list,
  				&rq->leaf_cfs_rq_list);
  			/*
  			 * We have reach the beg of a tree so we can reset
  			 * tmp_alone_branch to the beginning of the list.
  			 */
  			rq->tmp_alone_branch = &rq->leaf_cfs_rq_list;
  		} else {
  			/*
  			 * The parent has not already been added so we want to
  			 * make sure that it will be put after us.
  			 * tmp_alone_branch points to the beg of the branch
  			 * where we will add parent.
  			 */
  			list_add_rcu(&cfs_rq->leaf_cfs_rq_list,
  				rq->tmp_alone_branch);
  			/*
  			 * update tmp_alone_branch to points to the new beg
  			 * of the branch
  			 */
  			rq->tmp_alone_branch = &cfs_rq->leaf_cfs_rq_list;
  		}
  
  		cfs_rq->on_list = 1;
  	}
  }
  
  static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
  {
  	if (cfs_rq->on_list) {
  		list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
  		cfs_rq->on_list = 0;
  	}
  }
  
  /* Iterate through all leaf cfs_rq's on a runqueue: */
  #define for_each_leaf_cfs_rq(rq, cfs_rq) \
  	list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list)
  
  /* Do the two (enqueued) entities belong to the same group ? */
  static inline struct cfs_rq *
  is_same_group(struct sched_entity *se, struct sched_entity *pse)
  {
  	if (se->cfs_rq == pse->cfs_rq)
  		return se->cfs_rq;
  
  	return NULL;
  }
  
  static inline struct sched_entity *parent_entity(struct sched_entity *se)
  {
  	return se->parent;
  }
  
  static void
  find_matching_se(struct sched_entity **se, struct sched_entity **pse)
  {
  	int se_depth, pse_depth;
  
  	/*
  	 * preemption test can be made between sibling entities who are in the
  	 * same cfs_rq i.e who have a common parent. Walk up the hierarchy of
  	 * both tasks until we find their ancestors who are siblings of common
  	 * parent.
  	 */
  
  	/* First walk up until both entities are at same depth */
  	se_depth = (*se)->depth;
  	pse_depth = (*pse)->depth;
  
  	while (se_depth > pse_depth) {
  		se_depth--;
  		*se = parent_entity(*se);
  	}
  
  	while (pse_depth > se_depth) {
  		pse_depth--;
  		*pse = parent_entity(*pse);
  	}
  
  	while (!is_same_group(*se, *pse)) {
  		*se = parent_entity(*se);
  		*pse = parent_entity(*pse);
  	}
  }
  
  #else	/* !CONFIG_FAIR_GROUP_SCHED */
  
  static inline struct task_struct *task_of(struct sched_entity *se)
  {
  	return container_of(se, struct task_struct, se);
  }
  
  static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
  {
  	return container_of(cfs_rq, struct rq, cfs);
  }
  
  #define entity_is_task(se)	1
  
  #define for_each_sched_entity(se) \
  		for (; se; se = NULL)
  
  static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
  {
  	return &task_rq(p)->cfs;
  }
  
  static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
  {
  	struct task_struct *p = task_of(se);
  	struct rq *rq = task_rq(p);
  
  	return &rq->cfs;
  }
  
  /* runqueue "owned" by this group */
  static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
  {
  	return NULL;
  }
  
  static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq)
  {
  }
  
  static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
  {
  }
  
  #define for_each_leaf_cfs_rq(rq, cfs_rq)	\
  		for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL)
  
  static inline struct sched_entity *parent_entity(struct sched_entity *se)
  {
  	return NULL;
  }
  
  static inline void
  find_matching_se(struct sched_entity **se, struct sched_entity **pse)
  {
  }
  
  #endif	/* CONFIG_FAIR_GROUP_SCHED */
  
  static __always_inline
  void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec);
  
  /**************************************************************
   * Scheduling class tree data structure manipulation methods:
   */
  
  static inline u64 max_vruntime(u64 max_vruntime, u64 vruntime)
  {
  	s64 delta = (s64)(vruntime - max_vruntime);
  	if (delta > 0)
  		max_vruntime = vruntime;
  
  	return max_vruntime;
  }
  
  static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime)
  {
  	s64 delta = (s64)(vruntime - min_vruntime);
  	if (delta < 0)
  		min_vruntime = vruntime;
  
  	return min_vruntime;
  }
  
  static inline int entity_before(struct sched_entity *a,
  				struct sched_entity *b)
  {
  	return (s64)(a->vruntime - b->vruntime) < 0;
  }
  
  static void update_min_vruntime(struct cfs_rq *cfs_rq)
  {
  	struct sched_entity *curr = cfs_rq->curr;
  	struct rb_node *leftmost = rb_first_cached(&cfs_rq->tasks_timeline);
  
  	u64 vruntime = cfs_rq->min_vruntime;
  
  	if (curr) {
  		if (curr->on_rq)
  			vruntime = curr->vruntime;
  		else
  			curr = NULL;
  	}
  
  	if (leftmost) { /* non-empty tree */
  		struct sched_entity *se;
  		se = rb_entry(leftmost, struct sched_entity, run_node);
  
  		if (!curr)
  			vruntime = se->vruntime;
  		else
  			vruntime = min_vruntime(vruntime, se->vruntime);
  	}
  
  	/* ensure we never gain time by being placed backwards. */
  	cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime);
  #ifndef CONFIG_64BIT
  	smp_wmb();
  	cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
  #endif
  }
  
  /*
   * Enqueue an entity into the rb-tree:
   */
  static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	struct rb_node **link = &cfs_rq->tasks_timeline.rb_root.rb_node;
  	struct rb_node *parent = NULL;
  	struct sched_entity *entry;
  	bool leftmost = true;
  
  	/*
  	 * Find the right place in the rbtree:
  	 */
  	while (*link) {
  		parent = *link;
  		entry = rb_entry(parent, struct sched_entity, run_node);
  		/*
  		 * We dont care about collisions. Nodes with
  		 * the same key stay together.
  		 */
  		if (entity_before(se, entry)) {
  			link = &parent->rb_left;
  		} else {
  			link = &parent->rb_right;
  			leftmost = false;
  		}
  	}
  
  	rb_link_node(&se->run_node, parent, link);
  	rb_insert_color_cached(&se->run_node,
  			       &cfs_rq->tasks_timeline, leftmost);
  }
  
  static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	rb_erase_cached(&se->run_node, &cfs_rq->tasks_timeline);
  }
  
  struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
  {
  	struct rb_node *left = rb_first_cached(&cfs_rq->tasks_timeline);
  
  	if (!left)
  		return NULL;
  
  	return rb_entry(left, struct sched_entity, run_node);
  }
  
  static struct sched_entity *__pick_next_entity(struct sched_entity *se)
  {
  	struct rb_node *next = rb_next(&se->run_node);
  
  	if (!next)
  		return NULL;
  
  	return rb_entry(next, struct sched_entity, run_node);
  }
  
  #ifdef CONFIG_SCHED_DEBUG
  struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
  {
  	struct rb_node *last = rb_last(&cfs_rq->tasks_timeline.rb_root);
  
  	if (!last)
  		return NULL;
  
  	return rb_entry(last, struct sched_entity, run_node);
  }
  #endif
  
  /**************************************************************
   * Scheduling class statistics methods:
   */
  
  int sched_proc_update_handler(struct ctl_table *table, int write,
  		void __user *buffer, size_t *lenp,
  		loff_t *ppos)
  {
  	int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
  	unsigned int factor = get_update_sysctl_factor();
  
  	if (ret || !write)
  		return ret;
  
  	sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency,
  					sysctl_sched_min_granularity);
  
  #define WRT_SYSCTL(name) \
  	(normalized_sysctl_##name = sysctl_##name / (factor))
  	WRT_SYSCTL(sched_min_granularity);
  	WRT_SYSCTL(sched_latency);
  	WRT_SYSCTL(sched_wakeup_granularity);
  #undef WRT_SYSCTL
  
  	return 0;
  }
  
  /*
   * delta /= w
   */
  static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se)
  {
  	if (unlikely(se->load.weight != NICE_0_LOAD))
  		delta = __calc_delta(delta, NICE_0_LOAD, &se->load);
  
  	return delta;
  }
  
  /*
   * The idea is to set a period in which each task runs once.
   *
   * When there are too many tasks (sched_nr_latency) we have to stretch
   * this period because otherwise the slices get too small.
   *
   * p = (nr <= nl) ? l : l*nr/nl
   */
  static u64 __sched_period(unsigned long nr_running)
  {
  	if (unlikely(nr_running > sched_nr_latency))
  		return nr_running * sysctl_sched_min_granularity;
  	else
  		return sysctl_sched_latency;
  }
  
  /*
   * We calculate the wall-time slice from the period by taking a part
   * proportional to the weight.
   *
   * s = p*P[w/rw]
   */
  static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq);
  
  	for_each_sched_entity(se) {
  		struct load_weight *load;
  		struct load_weight lw;
  
  		cfs_rq = cfs_rq_of(se);
  		load = &cfs_rq->load;
  
  		if (unlikely(!se->on_rq)) {
  			lw = cfs_rq->load;
  
  			update_load_add(&lw, se->load.weight);
  			load = &lw;
  		}
  		slice = __calc_delta(slice, se->load.weight, load);
  	}
  	return slice;
  }
  
  /*
   * We calculate the vruntime slice of a to-be-inserted task.
   *
   * vs = s/w
   */
  static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	return calc_delta_fair(sched_slice(cfs_rq, se), se);
  }
  
  #ifdef CONFIG_SMP
  
  #include "sched-pelt.h"
  
  static int select_idle_sibling(struct task_struct *p, int prev_cpu, int cpu);
  static unsigned long task_h_load(struct task_struct *p);
  static unsigned long capacity_of(int cpu);
  
  /* Give new sched_entity start runnable values to heavy its load in infant time */
  void init_entity_runnable_average(struct sched_entity *se)
  {
  	struct sched_avg *sa = &se->avg;
  
  	memset(sa, 0, sizeof(*sa));
  	/*
  	 * util_avg is initialized in post_init_entity_util_avg.
  	 * util_est should start from zero.
  	 * sched_avg's period_contrib should be strictly less then 1024, so
  	 * we give it 1023 to make sure it is almost a period (1024us), and
  	 * will definitely be update (after enqueue).
  	 */
  	sa->period_contrib = 1023;
  	/*
  	 * Tasks are intialized with full load to be seen as heavy tasks until
  	 * they get a chance to stabilize to their real load level.
  	 * Group entities are intialized with zero load to reflect the fact that
  	 * nothing has been attached to the task group yet.
  	 */
  	if (entity_is_task(se))
  		sa->load_avg = scale_load_down(se->load.weight);
  	sa->load_sum = sa->load_avg * LOAD_AVG_MAX;
  #ifdef CONFIG_HISI_EAS_SCHED
  	sa->util_avg = SCHED_CAPACITY_SCALE >> 1;
  	sa->util_sum = sa->util_avg * LOAD_AVG_MAX;
  #endif
  	/* when this task enqueue'ed, it will contribute to its cfs_rq's load_avg */
  }
  
  static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq);
  static void attach_entity_cfs_rq(struct sched_entity *se);
  
  /*
   * With new tasks being created, their initial util_avgs are extrapolated
   * based on the cfs_rq's current util_avg:
   *
   *   util_avg = cfs_rq->util_avg / (cfs_rq->load_avg + 1) * se.load.weight
   *
   * However, in many cases, the above util_avg does not give a desired
   * value. Moreover, the sum of the util_avgs may be divergent, such
   * as when the series is a harmonic series.
   *
   * To solve this problem, we also cap the util_avg of successive tasks to
   * only 1/2 of the left utilization budget:
   *
   *   util_avg_cap = (cpu_scale - cfs_rq->avg.util_avg) / 2^n
   *
   * where n denotes the nth task and cpu_scale the CPU capacity.
   *
   * For example, for a CPU with 1024 of capacity, a simplest series from
   * the beginning would be like:
   *
   *  task  util_avg: 512, 256, 128,  64,  32,   16,    8, ...
   * cfs_rq util_avg: 512, 768, 896, 960, 992, 1008, 1016, ...
   *
   * Finally, that extrapolated util_avg is clamped to the cap (util_avg_cap)
   * if util_avg > util_avg_cap.
   */
  void post_init_entity_util_avg(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  #ifndef CONFIG_HISI_EAS_SCHED
  	struct sched_avg *sa = &se->avg;
  	long cpu_scale = arch_scale_cpu_capacity(NULL, cpu_of(rq_of(cfs_rq)));
  	long cap = (long)(cpu_scale - cfs_rq->avg.util_avg) / 2;
  
  	if (cap > 0) {
  		if (cfs_rq->avg.util_avg != 0) {
  			sa->util_avg  = cfs_rq->avg.util_avg * se->load.weight;
  			sa->util_avg /= (cfs_rq->avg.load_avg + 1);
  
  			if (sa->util_avg > cap)
  				sa->util_avg = cap;
  		} else {
  			sa->util_avg = cap;
  		}
  		sa->util_sum = sa->util_avg * LOAD_AVG_MAX;
  	}
  #endif
  
  	if (entity_is_task(se)) {
  		struct task_struct *p = task_of(se);
  		if (p->sched_class != &fair_sched_class) {
  			/*
  			 * For !fair tasks do:
  			 *
  			update_cfs_rq_load_avg(now, cfs_rq);
  			attach_entity_load_avg(cfs_rq, se);
  			switched_from_fair(rq, p);
  			 *
  			 * such that the next switched_to_fair() has the
  			 * expected state.
  			 */
  			se->avg.last_update_time = cfs_rq_clock_task(cfs_rq);
  			return;
  		}
  	}
  
  	attach_entity_cfs_rq(se);
  }
  
  #else /* !CONFIG_SMP */
  void init_entity_runnable_average(struct sched_entity *se)
  {
  }
  void post_init_entity_util_avg(struct sched_entity *se)
  {
  }
  static void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
  {
  }
  #endif /* CONFIG_SMP */
  
  /*
   * Update the current task's runtime statistics.
   */
  static void update_curr(struct cfs_rq *cfs_rq)
  {
  	struct sched_entity *curr = cfs_rq->curr;
  	u64 now = rq_clock_task(rq_of(cfs_rq));
  	u64 delta_exec;
  
  	if (unlikely(!curr))
  		return;
  
  	delta_exec = now - curr->exec_start;
  	if (unlikely((s64)delta_exec <= 0))
  		return;
  
  	curr->exec_start = now;
  
  	schedstat_set(curr->statistics.exec_max,
  		      max(delta_exec, curr->statistics.exec_max));
  
  	curr->sum_exec_runtime += delta_exec;
  #ifdef CONFIG_SCHED_HWSTATUS
  	if(cpu_of(rq_of(cfs_rq)) < 4)
  		curr->statistics.hwstatus.sum_exec_runtime_ltt += delta_exec;
  	else if(cpu_of(rq_of(cfs_rq)) < 6)
  		curr->statistics.hwstatus.sum_exec_runtime_mid += delta_exec;
  	else
  		curr->statistics.hwstatus.sum_exec_runtime_big += delta_exec;
  #endif
  	schedstat_add(cfs_rq->exec_clock, delta_exec);
  
  	curr->vruntime += calc_delta_fair(delta_exec, curr);
  	update_min_vruntime(cfs_rq);
  
  	if (entity_is_task(curr)) {
  		struct task_struct *curtask = task_of(curr);
  
  		trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
  		cpuacct_charge(curtask, delta_exec);
  		account_group_exec_runtime(curtask, delta_exec);
  	}
  
  	account_cfs_rq_runtime(cfs_rq, delta_exec);
  }
  
  static void update_curr_fair(struct rq *rq)
  {
  	update_curr(cfs_rq_of(&rq->curr->se));
  }
  
  static inline void
  update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	u64 wait_start, prev_wait_start;
  
  	if (!schedstat_enabled())
  		return;
  
  	wait_start = rq_clock(rq_of(cfs_rq));
  	prev_wait_start = schedstat_val(se->statistics.wait_start);
  
  	if (entity_is_task(se) && task_on_rq_migrating(task_of(se)) &&
  	    likely(wait_start > prev_wait_start))
  		wait_start -= prev_wait_start;
  
  	schedstat_set(se->statistics.wait_start, wait_start);
  }
  
  static inline void
  update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	struct task_struct *p;
  	u64 delta;
  
  	if (!schedstat_enabled())
  		return;
  
  	delta = rq_clock(rq_of(cfs_rq)) - schedstat_val(se->statistics.wait_start);
  
  	if (entity_is_task(se)) {
  		p = task_of(se);
  #ifdef CONFIG_HISI_ED_TASK
  		p->last_wake_wait_sum += delta;
  #endif
  		if (task_on_rq_migrating(p)) {
  			/*
  			 * Preserve migrating task's wait time so wait_start
  			 * time stamp can be adjusted to accumulate wait time
  			 * prior to migration.
  			 */
  			schedstat_set(se->statistics.wait_start, delta);
  			return;
  		}
  		trace_sched_stat_wait(p, delta);
  	}
  
  	schedstat_set(se->statistics.wait_max,
  		      max(schedstat_val(se->statistics.wait_max), delta));
  	schedstat_inc(se->statistics.wait_count);
  	schedstat_add(se->statistics.wait_sum, delta);
  	schedstat_set(se->statistics.wait_start, 0);
  }
  
  static inline void
  update_stats_enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	struct task_struct *tsk = NULL;
  	u64 sleep_start, block_start;
  
  	if (!schedstat_enabled())
  		return;
  
  	sleep_start = schedstat_val(se->statistics.sleep_start);
  	block_start = schedstat_val(se->statistics.block_start);
  
  	if (entity_is_task(se))
  		tsk = task_of(se);
  
  	if (sleep_start) {
  		u64 delta = rq_clock(rq_of(cfs_rq)) - sleep_start;
  
  		if ((s64)delta < 0)
  			delta = 0;
  
  		if (unlikely(delta > schedstat_val(se->statistics.sleep_max)))
  			schedstat_set(se->statistics.sleep_max, delta);
  
  		schedstat_set(se->statistics.sleep_start, 0);
  		schedstat_add(se->statistics.sum_sleep_runtime, delta);
  #ifdef CONFIG_SCHED_HWSTATUS
  		se->statistics.hwstatus.sleep_count++;
  #endif
  
  		if (tsk) {
  			account_scheduler_latency(tsk, delta >> 10, 1);
  			trace_sched_stat_sleep(tsk, delta);
  		}
  	}
  	if (block_start) {
  		u64 delta = rq_clock(rq_of(cfs_rq)) - block_start;
  
  		if ((s64)delta < 0)
  			delta = 0;
  
  		if (unlikely(delta > schedstat_val(se->statistics.block_max)))
  			schedstat_set(se->statistics.block_max, delta);
  
  		schedstat_set(se->statistics.block_start, 0);
  		schedstat_add(se->statistics.sum_sleep_runtime, delta);
  
  		if (tsk) {
  			if (tsk->in_iowait) {
  #ifdef CONFIG_SCHED_HWSTATUS
  				if(unlikely(delta > se->statistics.hwstatus.iowait_max)) {
  					se->statistics.hwstatus.iowait_max = delta;
  					sched_hwstatus_iodelay_caller(tsk, delta);
  				}
  
  #ifdef CONFIG_HW_VIP_THREAD
  		/*
  		 * Blocking time is in units of nanosecs, so shift by
  		 * 20 to get a milliseconds-range estimation of the
  		 * amount of time that the task spent sleeping:
  		 */
  		if (tsk && tsk->static_vip && (tsk->pid == tsk->tgid))
  			sched_account_ui_thread_io_block_counts(delta >> 20);
  #endif
  #endif
  				schedstat_add(se->statistics.iowait_sum, delta);
  				schedstat_inc(se->statistics.iowait_count);
  				trace_sched_stat_iowait(tsk, delta);
  			}
  #ifdef CONFIG_SCHED_HWSTATUS
  			if(!tsk->in_iowait) {
  				if(unlikely(delta > se->statistics.hwstatus.dstate_block_max)) {
  					se->statistics.hwstatus.dstate_block_max = delta;
  					sched_hwstatus_iodelay_caller(tsk, delta);
  				}
  				se->statistics.hwstatus.dstate_block_sum += delta;
  				se->statistics.hwstatus.dstate_block_count++;
  			}
  #endif
  			trace_sched_stat_blocked(tsk, delta);
  			trace_sched_blocked_reason(tsk, delta);
  
  			/*
  			 * Blocking time is in units of nanosecs, so shift by
  			 * 20 to get a milliseconds-range estimation of the
  			 * amount of time that the task spent sleeping:
  			 */
  			if (unlikely(prof_on == SLEEP_PROFILING)) {
  				profile_hits(SLEEP_PROFILING,
  						(void *)get_wchan(tsk),
  						delta >> 20);
  			}
  			account_scheduler_latency(tsk, delta >> 10, 0);
  		}
  	}
  }
  
  /*
   * Task is being enqueued - update stats:
   */
  static inline void
  update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
  {
  	if (!schedstat_enabled())
  		return;
  
  	/*
  	 * Are we enqueueing a waiting task? (for current tasks
  	 * a dequeue/enqueue event is a NOP)
  	 */
  	if (se != cfs_rq->curr)
  		update_stats_wait_start(cfs_rq, se);
  
  	if (flags & ENQUEUE_WAKEUP)
  		update_stats_enqueue_sleeper(cfs_rq, se);
  }
  
  static inline void
  update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
  {
  
  	if (!schedstat_enabled())
  		return;
  
  	/*
  	 * Mark the end of the wait period if dequeueing a
  	 * waiting task:
  	 */
  	if (se != cfs_rq->curr)
  		update_stats_wait_end(cfs_rq, se);
  
  	if ((flags & DEQUEUE_SLEEP) && entity_is_task(se)) {
  		struct task_struct *tsk = task_of(se);
  
  		if (tsk->state & TASK_INTERRUPTIBLE)
  			schedstat_set(se->statistics.sleep_start,
  				      rq_clock(rq_of(cfs_rq)));
  		if (tsk->state & TASK_UNINTERRUPTIBLE)
  			schedstat_set(se->statistics.block_start,
  				      rq_clock(rq_of(cfs_rq)));
  	}
  }
  
  /*
   * We are picking a new current task - update its stats:
   */
  static inline void
  update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	/*
  	 * We are starting a new run period:
  	 */
  	se->exec_start = rq_clock_task(rq_of(cfs_rq));
  }
  
  /**************************************************
   * Scheduling class queueing methods:
   */
  
  #ifdef CONFIG_NUMA_BALANCING
  /*
   * Approximate time to scan a full NUMA task in ms. The task scan period is
   * calculated based on the tasks virtual memory size and
   * numa_balancing_scan_size.
   */
  unsigned int sysctl_numa_balancing_scan_period_min = 1000;
  unsigned int sysctl_numa_balancing_scan_period_max = 60000;
  
  /* Portion of address space to scan in MB */
  unsigned int sysctl_numa_balancing_scan_size = 256;
  
  /* Scan @scan_size MB every @scan_period after an initial @scan_delay in ms */
  unsigned int sysctl_numa_balancing_scan_delay = 1000;
  
  struct numa_group {
  	atomic_t refcount;
  
  	spinlock_t lock; /* nr_tasks, tasks */
  	int nr_tasks;
  	pid_t gid;
  	int active_nodes;
  
  	struct rcu_head rcu;
  	unsigned long total_faults;
  	unsigned long max_faults_cpu;
  	/*
  	 * Faults_cpu is used to decide whether memory should move
  	 * towards the CPU. As a consequence, these stats are weighted
  	 * more by CPU use than by memory faults.
  	 */
  	unsigned long *faults_cpu;
  	unsigned long faults[0];
  };
  
  static inline unsigned long group_faults_priv(struct numa_group *ng);
  static inline unsigned long group_faults_shared(struct numa_group *ng);
  
  static unsigned int task_nr_scan_windows(struct task_struct *p)
  {
  	unsigned long rss = 0;
  	unsigned long nr_scan_pages;
  
  	/*
  	 * Calculations based on RSS as non-present and empty pages are skipped
  	 * by the PTE scanner and NUMA hinting faults should be trapped based
  	 * on resident pages
  	 */
  	nr_scan_pages = sysctl_numa_balancing_scan_size << (20 - PAGE_SHIFT);
  	rss = get_mm_rss(p->mm);
  	if (!rss)
  		rss = nr_scan_pages;
  
  	rss = round_up(rss, nr_scan_pages);
  	return rss / nr_scan_pages;
  }
  
  /* For sanitys sake, never scan more PTEs than MAX_SCAN_WINDOW MB/sec. */
  #define MAX_SCAN_WINDOW 2560
  
  static unsigned int task_scan_min(struct task_struct *p)
  {
  	unsigned int scan_size = READ_ONCE(sysctl_numa_balancing_scan_size);
  	unsigned int scan, floor;
  	unsigned int windows = 1;
  
  	if (scan_size < MAX_SCAN_WINDOW)
  		windows = MAX_SCAN_WINDOW / scan_size;
  	floor = 1000 / windows;
  
  	scan = sysctl_numa_balancing_scan_period_min / task_nr_scan_windows(p);
  	return max_t(unsigned int, floor, scan);
  }
  
  static unsigned int task_scan_start(struct task_struct *p)
  {
  	unsigned long smin = task_scan_min(p);
  	unsigned long period = smin;
  
  	/* Scale the maximum scan period with the amount of shared memory. */
  	if (p->numa_group) {
  		struct numa_group *ng = p->numa_group;
  		unsigned long shared = group_faults_shared(ng);
  		unsigned long private = group_faults_priv(ng);
  
  		period *= atomic_read(&ng->refcount);
  		period *= shared + 1;
  		period /= private + shared + 1;
  	}
  
  	return max(smin, period);
  }
  
  static unsigned int task_scan_max(struct task_struct *p)
  {
  	unsigned long smin = task_scan_min(p);
  	unsigned long smax;
  
  	/* Watch for min being lower than max due to floor calculations */
  	smax = sysctl_numa_balancing_scan_period_max / task_nr_scan_windows(p);
  
  	/* Scale the maximum scan period with the amount of shared memory. */
  	if (p->numa_group) {
  		struct numa_group *ng = p->numa_group;
  		unsigned long shared = group_faults_shared(ng);
  		unsigned long private = group_faults_priv(ng);
  		unsigned long period = smax;
  
  		period *= atomic_read(&ng->refcount);
  		period *= shared + 1;
  		period /= private + shared + 1;
  
  		smax = max(smax, period);
  	}
  
  	return max(smin, smax);
  }
  
  static void account_numa_enqueue(struct rq *rq, struct task_struct *p)
  {
  	rq->nr_numa_running += (p->numa_preferred_nid != -1);
  	rq->nr_preferred_running += (p->numa_preferred_nid == task_node(p));
  }
  
  static void account_numa_dequeue(struct rq *rq, struct task_struct *p)
  {
  	rq->nr_numa_running -= (p->numa_preferred_nid != -1);
  	rq->nr_preferred_running -= (p->numa_preferred_nid == task_node(p));
  }
  
  /* Shared or private faults. */
  #define NR_NUMA_HINT_FAULT_TYPES 2
  
  /* Memory and CPU locality */
  #define NR_NUMA_HINT_FAULT_STATS (NR_NUMA_HINT_FAULT_TYPES * 2)
  
  /* Averaged statistics, and temporary buffers. */
  #define NR_NUMA_HINT_FAULT_BUCKETS (NR_NUMA_HINT_FAULT_STATS * 2)
  
  pid_t task_numa_group_id(struct task_struct *p)
  {
  	return p->numa_group ? p->numa_group->gid : 0;
  }
  
  /*
   * The averaged statistics, shared & private, memory & cpu,
   * occupy the first half of the array. The second half of the
   * array is for current counters, which are averaged into the
   * first set by task_numa_placement.
   */
  static inline int task_faults_idx(enum numa_faults_stats s, int nid, int priv)
  {
  	return NR_NUMA_HINT_FAULT_TYPES * (s * nr_node_ids + nid) + priv;
  }
  
  static inline unsigned long task_faults(struct task_struct *p, int nid)
  {
  	if (!p->numa_faults)
  		return 0;
  
  	return p->numa_faults[task_faults_idx(NUMA_MEM, nid, 0)] +
  		p->numa_faults[task_faults_idx(NUMA_MEM, nid, 1)];
  }
  
  static inline unsigned long group_faults(struct task_struct *p, int nid)
  {
  	if (!p->numa_group)
  		return 0;
  
  	return p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 0)] +
  		p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 1)];
  }
  
  static inline unsigned long group_faults_cpu(struct numa_group *group, int nid)
  {
  	return group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 0)] +
  		group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 1)];
  }
  
  static inline unsigned long group_faults_priv(struct numa_group *ng)
  {
  	unsigned long faults = 0;
  	int node;
  
  	for_each_online_node(node) {
  		faults += ng->faults[task_faults_idx(NUMA_MEM, node, 1)];
  	}
  
  	return faults;
  }
  
  static inline unsigned long group_faults_shared(struct numa_group *ng)
  {
  	unsigned long faults = 0;
  	int node;
  
  	for_each_online_node(node) {
  		faults += ng->faults[task_faults_idx(NUMA_MEM, node, 0)];
  	}
  
  	return faults;
  }
  
  /*
   * A node triggering more than 1/3 as many NUMA faults as the maximum is
   * considered part of a numa group's pseudo-interleaving set. Migrations
   * between these nodes are slowed down, to allow things to settle down.
   */
  #define ACTIVE_NODE_FRACTION 3
  
  static bool numa_is_active_node(int nid, struct numa_group *ng)
  {
  	return group_faults_cpu(ng, nid) * ACTIVE_NODE_FRACTION > ng->max_faults_cpu;
  }
  
  /* Handle placement on systems where not all nodes are directly connected. */
  static unsigned long score_nearby_nodes(struct task_struct *p, int nid,
  					int maxdist, bool task)
  {
  	unsigned long score = 0;
  	int node;
  
  	/*
  	 * All nodes are directly connected, and the same distance
  	 * from each other. No need for fancy placement algorithms.
  	 */
  	if (sched_numa_topology_type == NUMA_DIRECT)
  		return 0;
  
  	/*
  	 * This code is called for each node, introducing N^2 complexity,
  	 * which should be ok given the number of nodes rarely exceeds 8.
  	 */
  	for_each_online_node(node) {
  		unsigned long faults;
  		int dist = node_distance(nid, node);
  
  		/*
  		 * The furthest away nodes in the system are not interesting
  		 * for placement; nid was already counted.
  		 */
  		if (dist == sched_max_numa_distance || node == nid)
  			continue;
  
  		/*
  		 * On systems with a backplane NUMA topology, compare groups
  		 * of nodes, and move tasks towards the group with the most
  		 * memory accesses. When comparing two nodes at distance
  		 * "hoplimit", only nodes closer by than "hoplimit" are part
  		 * of each group. Skip other nodes.
  		 */
  		if (sched_numa_topology_type == NUMA_BACKPLANE &&
  					dist > maxdist)
  			continue;
  
  		/* Add up the faults from nearby nodes. */
  		if (task)
  			faults = task_faults(p, node);
  		else
  			faults = group_faults(p, node);
  
  		/*
  		 * On systems with a glueless mesh NUMA topology, there are
  		 * no fixed "groups of nodes". Instead, nodes that are not
  		 * directly connected bounce traffic through intermediate
  		 * nodes; a numa_group can occupy any set of nodes.
  		 * The further away a node is, the less the faults count.
  		 * This seems to result in good task placement.
  		 */
  		if (sched_numa_topology_type == NUMA_GLUELESS_MESH) {
  			faults *= (sched_max_numa_distance - dist);
  			faults /= (sched_max_numa_distance - LOCAL_DISTANCE);
  		}
  
  		score += faults;
  	}
  
  	return score;
  }
  
  /*
   * These return the fraction of accesses done by a particular task, or
   * task group, on a particular numa node.  The group weight is given a
   * larger multiplier, in order to group tasks together that are almost
   * evenly spread out between numa nodes.
   */
  static inline unsigned long task_weight(struct task_struct *p, int nid,
  					int dist)
  {
  	unsigned long faults, total_faults;
  
  	if (!p->numa_faults)
  		return 0;
  
  	total_faults = p->total_numa_faults;
  
  	if (!total_faults)
  		return 0;
  
  	faults = task_faults(p, nid);
  	faults += score_nearby_nodes(p, nid, dist, true);
  
  	return 1000 * faults / total_faults;
  }
  
  static inline unsigned long group_weight(struct task_struct *p, int nid,
  					 int dist)
  {
  	unsigned long faults, total_faults;
  
  	if (!p->numa_group)
  		return 0;
  
  	total_faults = p->numa_group->total_faults;
  
  	if (!total_faults)
  		return 0;
  
  	faults = group_faults(p, nid);
  	faults += score_nearby_nodes(p, nid, dist, false);
  
  	return 1000 * faults / total_faults;
  }
  
  bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
  				int src_nid, int dst_cpu)
  {
  	struct numa_group *ng = p->numa_group;
  	int dst_nid = cpu_to_node(dst_cpu);
  	int last_cpupid, this_cpupid;
  
  	this_cpupid = cpu_pid_to_cpupid(dst_cpu, current->pid);
  
  	/*
  	 * Multi-stage node selection is used in conjunction with a periodic
  	 * migration fault to build a temporal task<->page relation. By using
  	 * a two-stage filter we remove short/unlikely relations.
  	 *
  	 * Using P(p) ~ n_p / n_t as per frequentist probability, we can equate
  	 * a task's usage of a particular page (n_p) per total usage of this
  	 * page (n_t) (in a given time-span) to a probability.
  	 *
  	 * Our periodic faults will sample this probability and getting the
  	 * same result twice in a row, given these samples are fully
  	 * independent, is then given by P(n)^2, provided our sample period
  	 * is sufficiently short compared to the usage pattern.
  	 *
  	 * This quadric squishes small probabilities, making it less likely we
  	 * act on an unlikely task<->page relation.
  	 */
  	last_cpupid = page_cpupid_xchg_last(page, this_cpupid);
  	if (!cpupid_pid_unset(last_cpupid) &&
  				cpupid_to_nid(last_cpupid) != dst_nid)
  		return false;
  
  	/* Always allow migrate on private faults */
  	if (cpupid_match_pid(p, last_cpupid))
  		return true;
  
  	/* A shared fault, but p->numa_group has not been set up yet. */
  	if (!ng)
  		return true;
  
  	/*
  	 * Destination node is much more heavily used than the source
  	 * node? Allow migration.
  	 */
  	if (group_faults_cpu(ng, dst_nid) > group_faults_cpu(ng, src_nid) *
  					ACTIVE_NODE_FRACTION)
  		return true;
  
  	/*
  	 * Distribute memory according to CPU & memory use on each node,
  	 * with 3/4 hysteresis to avoid unnecessary memory migrations:
  	 *
  	 * faults_cpu(dst)   3   faults_cpu(src)
  	 * --------------- * - > ---------------
  	 * faults_mem(dst)   4   faults_mem(src)
  	 */
  	return group_faults_cpu(ng, dst_nid) * group_faults(p, src_nid) * 3 >
  	       group_faults_cpu(ng, src_nid) * group_faults(p, dst_nid) * 4;
  }
  
  static unsigned long weighted_cpuload(struct rq *rq);
  static unsigned long source_load(int cpu, int type);
  static unsigned long target_load(int cpu, int type);
  
  /* Cached statistics for all CPUs within a node */
  struct numa_stats {
  	unsigned long nr_running;
  	unsigned long load;
  
  	/* Total compute capacity of CPUs on a node */
  	unsigned long compute_capacity;
  
  	/* Approximate capacity in terms of runnable tasks on a node */
  	unsigned long task_capacity;
  	int has_free_capacity;
  };
  
  /*
   * XXX borrowed from update_sg_lb_stats
   */
  static void update_numa_stats(struct numa_stats *ns, int nid)
  {
  	int smt, cpu, cpus = 0;
  	unsigned long capacity;
  
  	memset(ns, 0, sizeof(*ns));
  	for_each_cpu(cpu, cpumask_of_node(nid)) {
  		struct rq *rq = cpu_rq(cpu);
  
  		ns->nr_running += rq->nr_running;
  		ns->load += weighted_cpuload(rq);
  		ns->compute_capacity += capacity_of(cpu);
  
  		cpus++;
  	}
  
  	/*
  	 * If we raced with hotplug and there are no CPUs left in our mask
  	 * the @ns structure is NULL'ed and task_numa_compare() will
  	 * not find this node attractive.
  	 *
  	 * We'll either bail at !has_free_capacity, or we'll detect a huge
  	 * imbalance and bail there.
  	 */
  	if (!cpus)
  		return;
  
  	/* smt := ceil(cpus / capacity), assumes: 1 < smt_power < 2 */
  	smt = DIV_ROUND_UP(SCHED_CAPACITY_SCALE * cpus, ns->compute_capacity);
  	capacity = cpus / smt; /* cores */
  
  	ns->task_capacity = min_t(unsigned, capacity,
  		DIV_ROUND_CLOSEST(ns->compute_capacity, SCHED_CAPACITY_SCALE));
  	ns->has_free_capacity = (ns->nr_running < ns->task_capacity);
  }
  
  struct task_numa_env {
  	struct task_struct *p;
  
  	int src_cpu, src_nid;
  	int dst_cpu, dst_nid;
  
  	struct numa_stats src_stats, dst_stats;
  
  	int imbalance_pct;
  	int dist;
  
  	struct task_struct *best_task;
  	long best_imp;
  	int best_cpu;
  };
  
  static void task_numa_assign(struct task_numa_env *env,
  			     struct task_struct *p, long imp)
  {
  	if (env->best_task)
  		put_task_struct(env->best_task);
  	if (p)
  		get_task_struct(p);
  
  	env->best_task = p;
  	env->best_imp = imp;
  	env->best_cpu = env->dst_cpu;
  }
  
  static bool load_too_imbalanced(long src_load, long dst_load,
  				struct task_numa_env *env)
  {
  	long imb, old_imb;
  	long orig_src_load, orig_dst_load;
  	long src_capacity, dst_capacity;
  
  	/*
  	 * The load is corrected for the CPU capacity available on each node.
  	 *
  	 * src_load        dst_load
  	 * ------------ vs ---------
  	 * src_capacity    dst_capacity
  	 */
  	src_capacity = env->src_stats.compute_capacity;
  	dst_capacity = env->dst_stats.compute_capacity;
  
  	/* We care about the slope of the imbalance, not the direction. */
  	if (dst_load < src_load)
  		swap(dst_load, src_load);
  
  	/* Is the difference below the threshold? */
  	imb = dst_load * src_capacity * 100 -
  	      src_load * dst_capacity * env->imbalance_pct;
  	if (imb <= 0)
  		return false;
  
  	/*
  	 * The imbalance is above the allowed threshold.
  	 * Compare it with the old imbalance.
  	 */
  	orig_src_load = env->src_stats.load;
  	orig_dst_load = env->dst_stats.load;
  
  	if (orig_dst_load < orig_src_load)
  		swap(orig_dst_load, orig_src_load);
  
  	old_imb = orig_dst_load * src_capacity * 100 -
  		  orig_src_load * dst_capacity * env->imbalance_pct;
  
  	/* Would this change make things worse? */
  	return (imb > old_imb);
  }
  
  /*
   * This checks if the overall compute and NUMA accesses of the system would
   * be improved if the source tasks was migrated to the target dst_cpu taking
   * into account that it might be best if task running on the dst_cpu should
   * be exchanged with the source task
   */
  static void task_numa_compare(struct task_numa_env *env,
  			      long taskimp, long groupimp)
  {
  	struct rq *src_rq = cpu_rq(env->src_cpu);
  	struct rq *dst_rq = cpu_rq(env->dst_cpu);
  	struct task_struct *cur;
  	long src_load, dst_load;
  	long load;
  	long imp = env->p->numa_group ? groupimp : taskimp;
  	long moveimp = imp;
  	int dist = env->dist;
  
  	rcu_read_lock();
  	cur = task_rcu_dereference(&dst_rq->curr);
  	if (cur && ((cur->flags & PF_EXITING) || is_idle_task(cur)))
  		cur = NULL;
  
  	/*
  	 * Because we have preemption enabled we can get migrated around and
  	 * end try selecting ourselves (current == env->p) as a swap candidate.
  	 */
  	if (cur == env->p)
  		goto unlock;
  
  	/*
  	 * "imp" is the fault differential for the source task between the
  	 * source and destination node. Calculate the total differential for
  	 * the source task and potential destination task. The more negative
  	 * the value is, the more rmeote accesses that would be expected to
  	 * be incurred if the tasks were swapped.
  	 */
  	if (cur) {
  		/* Skip this swap candidate if cannot move to the source cpu */
  		if (!cpumask_test_cpu(env->src_cpu, &cur->cpus_allowed))
  			goto unlock;
  
  		/*
  		 * If dst and source tasks are in the same NUMA group, or not
  		 * in any group then look only at task weights.
  		 */
  		if (cur->numa_group == env->p->numa_group) {
  			imp = taskimp + task_weight(cur, env->src_nid, dist) -
  			      task_weight(cur, env->dst_nid, dist);
  			/*
  			 * Add some hysteresis to prevent swapping the
  			 * tasks within a group over tiny differences.
  			 */
  			if (cur->numa_group)
  				imp -= imp/16;
  		} else {
  			/*
  			 * Compare the group weights. If a task is all by
  			 * itself (not part of a group), use the task weight
  			 * instead.
  			 */
  			if (cur->numa_group)
  				imp += group_weight(cur, env->src_nid, dist) -
  				       group_weight(cur, env->dst_nid, dist);
  			else
  				imp += task_weight(cur, env->src_nid, dist) -
  				       task_weight(cur, env->dst_nid, dist);
  		}
  	}
  
  	if (imp <= env->best_imp && moveimp <= env->best_imp)
  		goto unlock;
  
  	if (!cur) {
  		/* Is there capacity at our destination? */
  		if (env->src_stats.nr_running <= env->src_stats.task_capacity &&
  		    !env->dst_stats.has_free_capacity)
  			goto unlock;
  
  		goto balance;
  	}
  
  	/* Balance doesn't matter much if we're running a task per cpu */
  	if (imp > env->best_imp && src_rq->nr_running == 1 &&
  			dst_rq->nr_running == 1)
  		goto assign;
  
  	/*
  	 * In the overloaded case, try and keep the load balanced.
  	 */
  balance:
  	load = task_h_load(env->p);
  	dst_load = env->dst_stats.load + load;
  	src_load = env->src_stats.load - load;
  
  	if (moveimp > imp && moveimp > env->best_imp) {
  		/*
  		 * If the improvement from just moving env->p direction is
  		 * better than swapping tasks around, check if a move is
  		 * possible. Store a slightly smaller score than moveimp,
  		 * so an actually idle CPU will win.
  		 */
  		if (!load_too_imbalanced(src_load, dst_load, env)) {
  			imp = moveimp - 1;
  			cur = NULL;
  			goto assign;
  		}
  	}
  
  	if (imp <= env->best_imp)
  		goto unlock;
  
  	if (cur) {
  		load = task_h_load(cur);
  		dst_load -= load;
  		src_load += load;
  	}
  
  	if (load_too_imbalanced(src_load, dst_load, env))
  		goto unlock;
  
  	/*
  	 * One idle CPU per node is evaluated for a task numa move.
  	 * Call select_idle_sibling to maybe find a better one.
  	 */
  	if (!cur) {
  		/*
  		 * select_idle_siblings() uses an per-cpu cpumask that
  		 * can be used from IRQ context.
  		 */
  		local_irq_disable();
  		env->dst_cpu = select_idle_sibling(env->p, env->src_cpu,
  						   env->dst_cpu);
  		local_irq_enable();
  	}
  
  assign:
  	task_numa_assign(env, cur, imp);
  unlock:
  	rcu_read_unlock();
  }
  
  static void task_numa_find_cpu(struct task_numa_env *env,
  				long taskimp, long groupimp)
  {
  	int cpu;
  
  	for_each_cpu(cpu, cpumask_of_node(env->dst_nid)) {
  		/* Skip this CPU if the source task cannot migrate */
  		if (!cpumask_test_cpu(cpu, &env->p->cpus_allowed))
  			continue;
  
  		env->dst_cpu = cpu;
  		task_numa_compare(env, taskimp, groupimp);
  	}
  }
  
  /* Only move tasks to a NUMA node less busy than the current node. */
  static bool numa_has_capacity(struct task_numa_env *env)
  {
  	struct numa_stats *src = &env->src_stats;
  	struct numa_stats *dst = &env->dst_stats;
  
  	if (src->has_free_capacity && !dst->has_free_capacity)
  		return false;
  
  	/*
  	 * Only consider a task move if the source has a higher load
  	 * than the destination, corrected for CPU capacity on each node.
  	 *
  	 *      src->load                dst->load
  	 * --------------------- vs ---------------------
  	 * src->compute_capacity    dst->compute_capacity
  	 */
  	if (src->load * dst->compute_capacity * env->imbalance_pct >
  
  	    dst->load * src->compute_capacity * 100)
  		return true;
  
  	return false;
  }
  
  static int task_numa_migrate(struct task_struct *p)
  {
  	struct task_numa_env env = {
  		.p = p,
  
  		.src_cpu = task_cpu(p),
  		.src_nid = task_node(p),
  
  		.imbalance_pct = 112,
  
  		.best_task = NULL,
  		.best_imp = 0,
  		.best_cpu = -1,
  	};
  	struct sched_domain *sd;
  	unsigned long taskweight, groupweight;
  	int nid, ret, dist;
  	long taskimp, groupimp;
  
  	/*
  	 * Pick the lowest SD_NUMA domain, as that would have the smallest
  	 * imbalance and would be the first to start moving tasks about.
  	 *
  	 * And we want to avoid any moving of tasks about, as that would create
  	 * random movement of tasks -- counter the numa conditions we're trying
  	 * to satisfy here.
  	 */
  	rcu_read_lock();
  	sd = rcu_dereference(per_cpu(sd_numa, env.src_cpu));
  	if (sd)
  		env.imbalance_pct = 100 + (sd->imbalance_pct - 100) / 2;
  	rcu_read_unlock();
  
  	/*
  	 * Cpusets can break the scheduler domain tree into smaller
  	 * balance domains, some of which do not cross NUMA boundaries.
  	 * Tasks that are "trapped" in such domains cannot be migrated
  	 * elsewhere, so there is no point in (re)trying.
  	 */
  	if (unlikely(!sd)) {
  		p->numa_preferred_nid = task_node(p);
  		return -EINVAL;
  	}
  
  	env.dst_nid = p->numa_preferred_nid;
  	dist = env.dist = node_distance(env.src_nid, env.dst_nid);
  	taskweight = task_weight(p, env.src_nid, dist);
  	groupweight = group_weight(p, env.src_nid, dist);
  	update_numa_stats(&env.src_stats, env.src_nid);
  	taskimp = task_weight(p, env.dst_nid, dist) - taskweight;
  	groupimp = group_weight(p, env.dst_nid, dist) - groupweight;
  	update_numa_stats(&env.dst_stats, env.dst_nid);
  
  	/* Try to find a spot on the preferred nid. */
  	if (numa_has_capacity(&env))
  		task_numa_find_cpu(&env, taskimp, groupimp);
  
  	/*
  	 * Look at other nodes in these cases:
  	 * - there is no space available on the preferred_nid
  	 * - the task is part of a numa_group that is interleaved across
  	 *   multiple NUMA nodes; in order to better consolidate the group,
  	 *   we need to check other locations.
  	 */
  	if (env.best_cpu == -1 || (p->numa_group && p->numa_group->active_nodes > 1)) {
  		for_each_online_node(nid) {
  			if (nid == env.src_nid || nid == p->numa_preferred_nid)
  				continue;
  
  			dist = node_distance(env.src_nid, env.dst_nid);
  			if (sched_numa_topology_type == NUMA_BACKPLANE &&
  						dist != env.dist) {
  				taskweight = task_weight(p, env.src_nid, dist);
  				groupweight = group_weight(p, env.src_nid, dist);
  			}
  
  			/* Only consider nodes where both task and groups benefit */
  			taskimp = task_weight(p, nid, dist) - taskweight;
  			groupimp = group_weight(p, nid, dist) - groupweight;
  			if (taskimp < 0 && groupimp < 0)
  				continue;
  
  			env.dist = dist;
  			env.dst_nid = nid;
  			update_numa_stats(&env.dst_stats, env.dst_nid);
  			if (numa_has_capacity(&env))
  				task_numa_find_cpu(&env, taskimp, groupimp);
  		}
  	}
  
  	/*
  	 * If the task is part of a workload that spans multiple NUMA nodes,
  	 * and is migrating into one of the workload's active nodes, remember
  	 * this node as the task's preferred numa node, so the workload can
  	 * settle down.
  	 * A task that migrated to a second choice node will be better off
  	 * trying for a better one later. Do not set the preferred node here.
  	 */
  	if (p->numa_group) {
  		struct numa_group *ng = p->numa_group;
  
  		if (env.best_cpu == -1)
  			nid = env.src_nid;
  		else
  			nid = env.dst_nid;
  
  		if (ng->active_nodes > 1 && numa_is_active_node(env.dst_nid, ng))
  			sched_setnuma(p, env.dst_nid);
  	}
  
  	/* No better CPU than the current one was found. */
  	if (env.best_cpu == -1)
  		return -EAGAIN;
  
  	/*
  	 * Reset the scan period if the task is being rescheduled on an
  	 * alternative node to recheck if the tasks is now properly placed.
  	 */
  	p->numa_scan_period = task_scan_start(p);
  
  	if (env.best_task == NULL) {
  		ret = migrate_task_to(p, env.best_cpu);
  		if (ret != 0)
  			trace_sched_stick_numa(p, env.src_cpu, env.best_cpu);
  		return ret;
  	}
  
  	ret = migrate_swap(p, env.best_task);
  	if (ret != 0)
  		trace_sched_stick_numa(p, env.src_cpu, task_cpu(env.best_task));
  	put_task_struct(env.best_task);
  	return ret;
  }
  
  /* Attempt to migrate a task to a CPU on the preferred node. */
  static void numa_migrate_preferred(struct task_struct *p)
  {
  	unsigned long interval = HZ;
  
  	/* This task has no NUMA fault statistics yet */
  	if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults))
  		return;
  
  	/* Periodically retry migrating the task to the preferred node */
  	interval = min(interval, msecs_to_jiffies(p->numa_scan_period) / 16);
  	p->numa_migrate_retry = jiffies + interval;
  
  	/* Success if task is already running on preferred CPU */
  	if (task_node(p) == p->numa_preferred_nid)
  		return;
  
  	/* Otherwise, try migrate to a CPU on the preferred node */
  	task_numa_migrate(p);
  }
  
  /*
   * Find out how many nodes on the workload is actively running on. Do this by
   * tracking the nodes from which NUMA hinting faults are triggered. This can
   * be different from the set of nodes where the workload's memory is currently
   * located.
   */
  static void numa_group_count_active_nodes(struct numa_group *numa_group)
  {
  	unsigned long faults, max_faults = 0;
  	int nid, active_nodes = 0;
  
  	for_each_online_node(nid) {
  		faults = group_faults_cpu(numa_group, nid);
  		if (faults > max_faults)
  			max_faults = faults;
  	}
  
  	for_each_online_node(nid) {
  		faults = group_faults_cpu(numa_group, nid);
  		if (faults * ACTIVE_NODE_FRACTION > max_faults)
  			active_nodes++;
  	}
  
  	numa_group->max_faults_cpu = max_faults;
  	numa_group->active_nodes = active_nodes;
  }
  
  /*
   * When adapting the scan rate, the period is divided into NUMA_PERIOD_SLOTS
   * increments. The more local the fault statistics are, the higher the scan
   * period will be for the next scan window. If local/(local+remote) ratio is
   * below NUMA_PERIOD_THRESHOLD (where range of ratio is 1..NUMA_PERIOD_SLOTS)
   * the scan period will decrease. Aim for 70% local accesses.
   */
  #define NUMA_PERIOD_SLOTS 10
  #define NUMA_PERIOD_THRESHOLD 7
  
  /*
   * Increase the scan period (slow down scanning) if the majority of
   * our memory is already on our local node, or if the majority of
   * the page accesses are shared with other processes.
   * Otherwise, decrease the scan period.
   */
  static void update_task_scan_period(struct task_struct *p,
  			unsigned long shared, unsigned long private)
  {
  	unsigned int period_slot;
  	int lr_ratio, ps_ratio;
  	int diff;
  
  	unsigned long remote = p->numa_faults_locality[0];
  	unsigned long local = p->numa_faults_locality[1];
  
  	/*
  	 * If there were no record hinting faults then either the task is
  	 * completely idle or all activity is areas that are not of interest
  	 * to automatic numa balancing. Related to that, if there were failed
  	 * migration then it implies we are migrating too quickly or the local
  	 * node is overloaded. In either case, scan slower
  	 */
  	if (local + shared == 0 || p->numa_faults_locality[2]) {
  		p->numa_scan_period = min(p->numa_scan_period_max,
  			p->numa_scan_period << 1);
  
  		p->mm->numa_next_scan = jiffies +
  			msecs_to_jiffies(p->numa_scan_period);
  
  		return;
  	}
  
  	/*
  	 * Prepare to scale scan period relative to the current period.
  	 *	 == NUMA_PERIOD_THRESHOLD scan period stays the same
  	 *       <  NUMA_PERIOD_THRESHOLD scan period decreases (scan faster)
  	 *	 >= NUMA_PERIOD_THRESHOLD scan period increases (scan slower)
  	 */
  	period_slot = DIV_ROUND_UP(p->numa_scan_period, NUMA_PERIOD_SLOTS);
  	lr_ratio = (local * NUMA_PERIOD_SLOTS) / (local + remote);
  	ps_ratio = (private * NUMA_PERIOD_SLOTS) / (private + shared);
  
  	if (ps_ratio >= NUMA_PERIOD_THRESHOLD) {
  		/*
  		 * Most memory accesses are local. There is no need to
  		 * do fast NUMA scanning, since memory is already local.
  		 */
  		int slot = ps_ratio - NUMA_PERIOD_THRESHOLD;
  		if (!slot)
  			slot = 1;
  		diff = slot * period_slot;
  	} else if (lr_ratio >= NUMA_PERIOD_THRESHOLD) {
  		/*
  		 * Most memory accesses are shared with other tasks.
  		 * There is no point in continuing fast NUMA scanning,
  		 * since other tasks may just move the memory elsewhere.
  		 */
  		int slot = lr_ratio - NUMA_PERIOD_THRESHOLD;
  		if (!slot)
  			slot = 1;
  		diff = slot * period_slot;
  	} else {
  		/*
  		 * Private memory faults exceed (SLOTS-THRESHOLD)/SLOTS,
  		 * yet they are not on the local NUMA node. Speed up
  		 * NUMA scanning to get the memory moved over.
  		 */
  		int ratio = max(lr_ratio, ps_ratio);
  		diff = -(NUMA_PERIOD_THRESHOLD - ratio) * period_slot;
  	}
  
  	p->numa_scan_period = clamp(p->numa_scan_period + diff,
  			task_scan_min(p), task_scan_max(p));
  	memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality));
  }
  
  /*
   * Get the fraction of time the task has been running since the last
   * NUMA placement cycle. The scheduler keeps similar statistics, but
   * decays those on a 32ms period, which is orders of magnitude off
   * from the dozens-of-seconds NUMA balancing period. Use the scheduler
   * stats only if the task is so new there are no NUMA statistics yet.
   */
  static u64 numa_get_avg_runtime(struct task_struct *p, u64 *period)
  {
  	u64 runtime, delta, now;
  	/* Use the start of this time slice to avoid calculations. */
  	now = p->se.exec_start;
  	runtime = p->se.sum_exec_runtime;
  
  	if (p->last_task_numa_placement) {
  		delta = runtime - p->last_sum_exec_runtime;
  		*period = now - p->last_task_numa_placement;
  
  		/* Avoid time going backwards, prevent potential divide error: */
  		if (unlikely((s64)*period < 0))
  			*period = 0;
  	} else {
  		delta = p->se.avg.load_sum / p->se.load.weight;
  		*period = LOAD_AVG_MAX;
  	}
  
  	p->last_sum_exec_runtime = runtime;
  	p->last_task_numa_placement = now;
  
  	return delta;
  }
  
  /*
   * Determine the preferred nid for a task in a numa_group. This needs to
   * be done in a way that produces consistent results with group_weight,
   * otherwise workloads might not converge.
   */
  static int preferred_group_nid(struct task_struct *p, int nid)
  {
  	nodemask_t nodes;
  	int dist;
  
  	/* Direct connections between all NUMA nodes. */
  	if (sched_numa_topology_type == NUMA_DIRECT)
  		return nid;
  
  	/*
  	 * On a system with glueless mesh NUMA topology, group_weight
  	 * scores nodes according to the number of NUMA hinting faults on
  	 * both the node itself, and on nearby nodes.
  	 */
  	if (sched_numa_topology_type == NUMA_GLUELESS_MESH) {
  		unsigned long score, max_score = 0;
  		int node, max_node = nid;
  
  		dist = sched_max_numa_distance;
  
  		for_each_online_node(node) {
  			score = group_weight(p, node, dist);
  			if (score > max_score) {
  				max_score = score;
  				max_node = node;
  			}
  		}
  		return max_node;
  	}
  
  	/*
  	 * Finding the preferred nid in a system with NUMA backplane
  	 * interconnect topology is more involved. The goal is to locate
  	 * tasks from numa_groups near each other in the system, and
  	 * untangle workloads from different sides of the system. This requires
  	 * searching down the hierarchy of node groups, recursively searching
  	 * inside the highest scoring group of nodes. The nodemask tricks
  	 * keep the complexity of the search down.
  	 */
  	nodes = node_online_map;
  	for (dist = sched_max_numa_distance; dist > LOCAL_DISTANCE; dist--) {
  		unsigned long max_faults = 0;
  		nodemask_t max_group = NODE_MASK_NONE;
  		int a, b;
  
  		/* Are there nodes at this distance from each other? */
  		if (!find_numa_distance(dist))
  			continue;
  
  		for_each_node_mask(a, nodes) {
  			unsigned long faults = 0;
  			nodemask_t this_group;
  			nodes_clear(this_group);
  
  			/* Sum group's NUMA faults; includes a==b case. */
  			for_each_node_mask(b, nodes) {
  				if (node_distance(a, b) < dist) {
  					faults += group_faults(p, b);
  					node_set(b, this_group);
  					node_clear(b, nodes);
  				}
  			}
  
  			/* Remember the top group. */
  			if (faults > max_faults) {
  				max_faults = faults;
  				max_group = this_group;
  				/*
  				 * subtle: at the smallest distance there is
  				 * just one node left in each "group", the
  				 * winner is the preferred nid.
  				 */
  				nid = a;
  			}
  		}
  		/* Next round, evaluate the nodes within max_group. */
  		if (!max_faults)
  			break;
  		nodes = max_group;
  	}
  	return nid;
  }
  
  static void task_numa_placement(struct task_struct *p)
  {
  	int seq, nid, max_nid = -1, max_group_nid = -1;
  	unsigned long max_faults = 0, max_group_faults = 0;
  	unsigned long fault_types[2] = { 0, 0 };
  	unsigned long total_faults;
  	u64 runtime, period;
  	spinlock_t *group_lock = NULL;
  
  	/*
  	 * The p->mm->numa_scan_seq field gets updated without
  	 * exclusive access. Use READ_ONCE() here to ensure
  	 * that the field is read in a single access:
  	 */
  	seq = READ_ONCE(p->mm->numa_scan_seq);
  	if (p->numa_scan_seq == seq)
  		return;
  	p->numa_scan_seq = seq;
  	p->numa_scan_period_max = task_scan_max(p);
  
  	total_faults = p->numa_faults_locality[0] +
  		       p->numa_faults_locality[1];
  	runtime = numa_get_avg_runtime(p, &period);
  
  	/* If the task is part of a group prevent parallel updates to group stats */
  	if (p->numa_group) {
  		group_lock = &p->numa_group->lock;
  		spin_lock_irq(group_lock);
  	}
  
  	/* Find the node with the highest number of faults */
  	for_each_online_node(nid) {
  		/* Keep track of the offsets in numa_faults array */
  		int mem_idx, membuf_idx, cpu_idx, cpubuf_idx;
  		unsigned long faults = 0, group_faults = 0;
  		int priv;
  
  		for (priv = 0; priv < NR_NUMA_HINT_FAULT_TYPES; priv++) {
  			long diff, f_diff, f_weight;
  
  			mem_idx = task_faults_idx(NUMA_MEM, nid, priv);
  			membuf_idx = task_faults_idx(NUMA_MEMBUF, nid, priv);
  			cpu_idx = task_faults_idx(NUMA_CPU, nid, priv);
  			cpubuf_idx = task_faults_idx(NUMA_CPUBUF, nid, priv);
  
  			/* Decay existing window, copy faults since last scan */
  			diff = p->numa_faults[membuf_idx] - p->numa_faults[mem_idx] / 2;
  			fault_types[priv] += p->numa_faults[membuf_idx];
  			p->numa_faults[membuf_idx] = 0;
  
  			/*
  			 * Normalize the faults_from, so all tasks in a group
  			 * count according to CPU use, instead of by the raw
  			 * number of faults. Tasks with little runtime have
  			 * little over-all impact on throughput, and thus their
  			 * faults are less important.
  			 */
  			f_weight = div64_u64(runtime << 16, period + 1);
  			f_weight = (f_weight * p->numa_faults[cpubuf_idx]) /
  				   (total_faults + 1);
  			f_diff = f_weight - p->numa_faults[cpu_idx] / 2;
  			p->numa_faults[cpubuf_idx] = 0;
  
  			p->numa_faults[mem_idx] += diff;
  			p->numa_faults[cpu_idx] += f_diff;
  			faults += p->numa_faults[mem_idx];
  			p->total_numa_faults += diff;
  			if (p->numa_group) {
  				/*
  				 * safe because we can only change our own group
  				 *
  				 * mem_idx represents the offset for a given
  				 * nid and priv in a specific region because it
  				 * is at the beginning of the numa_faults array.
  				 */
  				p->numa_group->faults[mem_idx] += diff;
  				p->numa_group->faults_cpu[mem_idx] += f_diff;
  				p->numa_group->total_faults += diff;
  				group_faults += p->numa_group->faults[mem_idx];
  			}
  		}
  
  		if (faults > max_faults) {
  			max_faults = faults;
  			max_nid = nid;
  		}
  
  		if (group_faults > max_group_faults) {
  			max_group_faults = group_faults;
  			max_group_nid = nid;
  		}
  	}
  
  	update_task_scan_period(p, fault_types[0], fault_types[1]);
  
  	if (p->numa_group) {
  		numa_group_count_active_nodes(p->numa_group);
  		spin_unlock_irq(group_lock);
  		max_nid = preferred_group_nid(p, max_group_nid);
  	}
  
  	if (max_faults) {
  		/* Set the new preferred node */
  		if (max_nid != p->numa_preferred_nid)
  			sched_setnuma(p, max_nid);
  
  		if (task_node(p) != p->numa_preferred_nid)
  			numa_migrate_preferred(p);
  	}
  }
  
  static inline int get_numa_group(struct numa_group *grp)
  {
  	return atomic_inc_not_zero(&grp->refcount);
  }
  
  static inline void put_numa_group(struct numa_group *grp)
  {
  	if (atomic_dec_and_test(&grp->refcount))
  		kfree_rcu(grp, rcu);
  }
  
  static void task_numa_group(struct task_struct *p, int cpupid, int flags,
  			int *priv)
  {
  	struct numa_group *grp, *my_grp;
  	struct task_struct *tsk;
  	bool join = false;
  	int cpu = cpupid_to_cpu(cpupid);
  	int i;
  
  	if (unlikely(!p->numa_group)) {
  		unsigned int size = sizeof(struct numa_group) +
  				    4*nr_node_ids*sizeof(unsigned long);
  
  		grp = kzalloc(size, GFP_KERNEL | __GFP_NOWARN);
  		if (!grp)
  			return;
  
  		atomic_set(&grp->refcount, 1);
  		grp->active_nodes = 1;
  		grp->max_faults_cpu = 0;
  		spin_lock_init(&grp->lock);
  		grp->gid = p->pid;
  		/* Second half of the array tracks nids where faults happen */
  		grp->faults_cpu = grp->faults + NR_NUMA_HINT_FAULT_TYPES *
  						nr_node_ids;
  
  		for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
  			grp->faults[i] = p->numa_faults[i];
  
  		grp->total_faults = p->total_numa_faults;
  
  		grp->nr_tasks++;
  		rcu_assign_pointer(p->numa_group, grp);
  	}
  
  	rcu_read_lock();
  	tsk = READ_ONCE(cpu_rq(cpu)->curr);
  
  	if (!cpupid_match_pid(tsk, cpupid))
  		goto no_join;
  
  	grp = rcu_dereference(tsk->numa_group);
  	if (!grp)
  		goto no_join;
  
  	my_grp = p->numa_group;
  	if (grp == my_grp)
  		goto no_join;
  
  	/*
  	 * Only join the other group if its bigger; if we're the bigger group,
  	 * the other task will join us.
  	 */
  	if (my_grp->nr_tasks > grp->nr_tasks)
  		goto no_join;
  
  	/*
  	 * Tie-break on the grp address.
  	 */
  	if (my_grp->nr_tasks == grp->nr_tasks && my_grp > grp)
  		goto no_join;
  
  	/* Always join threads in the same process. */
  	if (tsk->mm == current->mm)
  		join = true;
  
  	/* Simple filter to avoid false positives due to PID collisions */
  	if (flags & TNF_SHARED)
  		join = true;
  
  	/* Update priv based on whether false sharing was detected */
  	*priv = !join;
  
  	if (join && !get_numa_group(grp))
  		goto no_join;
  
  	rcu_read_unlock();
  
  	if (!join)
  		return;
  
  	BUG_ON(irqs_disabled());
  	double_lock_irq(&my_grp->lock, &grp->lock);
  
  	for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++) {
  		my_grp->faults[i] -= p->numa_faults[i];
  		grp->faults[i] += p->numa_faults[i];
  	}
  	my_grp->total_faults -= p->total_numa_faults;
  	grp->total_faults += p->total_numa_faults;
  
  	my_grp->nr_tasks--;
  	grp->nr_tasks++;
  
  	spin_unlock(&my_grp->lock);
  	spin_unlock_irq(&grp->lock);
  
  	rcu_assign_pointer(p->numa_group, grp);
  
  	put_numa_group(my_grp);
  	return;
  
  no_join:
  	rcu_read_unlock();
  	return;
  }
  
  /*
   * Get rid of NUMA staticstics associated with a task (either current or dead).
   * If @final is set, the task is dead and has reached refcount zero, so we can
   * safely free all relevant data structures. Otherwise, there might be
   * concurrent reads from places like load balancing and procfs, and we should
   * reset the data back to default state without freeing ->numa_faults.
   */
  void task_numa_free(struct task_struct *p, bool final)
  {
  	struct numa_group *grp = p->numa_group;
  	unsigned long *numa_faults = p->numa_faults;
  	unsigned long flags;
  	int i;
  
  	if (!numa_faults)
  		return;
  
  	if (grp) {
  		spin_lock_irqsave(&grp->lock, flags);
  		for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
  			grp->faults[i] -= p->numa_faults[i];
  		grp->total_faults -= p->total_numa_faults;
  
  		grp->nr_tasks--;
  		spin_unlock_irqrestore(&grp->lock, flags);
  		RCU_INIT_POINTER(p->numa_group, NULL);
  		put_numa_group(grp);
  	}
  
  	if (final) {
  		p->numa_faults = NULL;
  		kfree(numa_faults);
  	} else {
  		p->total_numa_faults = 0;
  		for (i = 0; i < NR_NUMA_HINT_FAULT_STATS * nr_node_ids; i++)
  			numa_faults[i] = 0;
  	}
  }
  
  /*
   * Got a PROT_NONE fault for a page on @node.
   */
  void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
  {
  	struct task_struct *p = current;
  	bool migrated = flags & TNF_MIGRATED;
  	int cpu_node = task_node(current);
  	int local = !!(flags & TNF_FAULT_LOCAL);
  	struct numa_group *ng;
  	int priv;
  
  	if (!static_branch_likely(&sched_numa_balancing))
  		return;
  
  	/* for example, ksmd faulting in a user's mm */
  	if (!p->mm)
  		return;
  
  	/* Allocate buffer to track faults on a per-node basis */
  	if (unlikely(!p->numa_faults)) {
  		int size = sizeof(*p->numa_faults) *
  			   NR_NUMA_HINT_FAULT_BUCKETS * nr_node_ids;
  
  		p->numa_faults = kzalloc(size, GFP_KERNEL|__GFP_NOWARN);
  		if (!p->numa_faults)
  			return;
  
  		p->total_numa_faults = 0;
  		memset(p->numa_faults_locality, 0, sizeof(p->numa_faults_locality));
  	}
  
  	/*
  	 * First accesses are treated as private, otherwise consider accesses
  	 * to be private if the accessing pid has not changed
  	 */
  	if (unlikely(last_cpupid == (-1 & LAST_CPUPID_MASK))) {
  		priv = 1;
  	} else {
  		priv = cpupid_match_pid(p, last_cpupid);
  		if (!priv && !(flags & TNF_NO_GROUP))
  			task_numa_group(p, last_cpupid, flags, &priv);
  	}
  
  	/*
  	 * If a workload spans multiple NUMA nodes, a shared fault that
  	 * occurs wholly within the set of nodes that the workload is
  	 * actively using should be counted as local. This allows the
  	 * scan rate to slow down when a workload has settled down.
  	 */
  	ng = p->numa_group;
  	if (!priv && !local && ng && ng->active_nodes > 1 &&
  				numa_is_active_node(cpu_node, ng) &&
  				numa_is_active_node(mem_node, ng))
  		local = 1;
  
  	task_numa_placement(p);
  
  	/*
  	 * Retry task to preferred node migration periodically, in case it
  	 * case it previously failed, or the scheduler moved us.
  	 */
  	if (time_after(jiffies, p->numa_migrate_retry))
  		numa_migrate_preferred(p);
  
  	if (migrated)
  		p->numa_pages_migrated += pages;
  	if (flags & TNF_MIGRATE_FAIL)
  		p->numa_faults_locality[2] += pages;
  
  	p->numa_faults[task_faults_idx(NUMA_MEMBUF, mem_node, priv)] += pages;
  	p->numa_faults[task_faults_idx(NUMA_CPUBUF, cpu_node, priv)] += pages;
  	p->numa_faults_locality[local] += pages;
  }
  
  static void reset_ptenuma_scan(struct task_struct *p)
  {
  	/*
  	 * We only did a read acquisition of the mmap sem, so
  	 * p->mm->numa_scan_seq is written to without exclusive access
  	 * and the update is not guaranteed to be atomic. That's not
  	 * much of an issue though, since this is just used for
  	 * statistical sampling. Use READ_ONCE/WRITE_ONCE, which are not
  	 * expensive, to avoid any form of compiler optimizations:
  	 */
  	WRITE_ONCE(p->mm->numa_scan_seq, READ_ONCE(p->mm->numa_scan_seq) + 1);
  	p->mm->numa_scan_offset = 0;
  }
  
  /*
   * The expensive part of numa migration is done from task_work context.
   * Triggered from task_tick_numa().
   */
  void task_numa_work(struct callback_head *work)
  {
  	unsigned long migrate, next_scan, now = jiffies;
  	struct task_struct *p = current;
  	struct mm_struct *mm = p->mm;
  	u64 runtime = p->se.sum_exec_runtime;
  	struct vm_area_struct *vma;
  	unsigned long start, end;
  	unsigned long nr_pte_updates = 0;
  	long pages, virtpages;
  
  	SCHED_WARN_ON(p != container_of(work, struct task_struct, numa_work));
  
  	work->next = work; /* protect against double add */
  	/*
  	 * Who cares about NUMA placement when they're dying.
  	 *
  	 * NOTE: make sure not to dereference p->mm before this check,
  	 * exit_task_work() happens _after_ exit_mm() so we could be called
  	 * without p->mm even though we still had it when we enqueued this
  	 * work.
  	 */
  	if (p->flags & PF_EXITING)
  		return;
  
  	if (!mm->numa_next_scan) {
  		mm->numa_next_scan = now +
  			msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
  	}
  
  	/*
  	 * Enforce maximal scan/migration frequency..
  	 */
  	migrate = mm->numa_next_scan;
  	if (time_before(now, migrate))
  		return;
  
  	if (p->numa_scan_period == 0) {
  		p->numa_scan_period_max = task_scan_max(p);
  		p->numa_scan_period = task_scan_start(p);
  	}
  
  	next_scan = now + msecs_to_jiffies(p->numa_scan_period);
  	if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate)
  		return;
  
  	/*
  	 * Delay this task enough that another task of this mm will likely win
  	 * the next time around.
  	 */
  	p->node_stamp += 2 * TICK_NSEC;
  
  	start = mm->numa_scan_offset;
  	pages = sysctl_numa_balancing_scan_size;
  	pages <<= 20 - PAGE_SHIFT; /* MB in pages */
  	virtpages = pages * 8;	   /* Scan up to this much virtual space */
  	if (!pages)
  		return;
  
  
  	if (!down_read_trylock(&mm->mmap_sem))
  		return;
  	vma = find_vma(mm, start);
  	if (!vma) {
  		reset_ptenuma_scan(p);
  		start = 0;
  		vma = mm->mmap;
  	}
  	for (; vma; vma = vma->vm_next) {
  		if (!vma_migratable(vma) || !vma_policy_mof(vma) ||
  			is_vm_hugetlb_page(vma) || (vma->vm_flags & VM_MIXEDMAP)) {
  			continue;
  		}
  
  		/*
  		 * Shared library pages mapped by multiple processes are not
  		 * migrated as it is expected they are cache replicated. Avoid
  		 * hinting faults in read-only file-backed mappings or the vdso
  		 * as migrating the pages will be of marginal benefit.
  		 */
  		if (!vma->vm_mm ||
  		    (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ)))
  			continue;
  
  		/*
  		 * Skip inaccessible VMAs to avoid any confusion between
  		 * PROT_NONE and NUMA hinting ptes
  		 */
  		if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
  			continue;
  
  		do {
  			start = max(start, vma->vm_start);
  			end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);
  			end = min(end, vma->vm_end);
  			nr_pte_updates = change_prot_numa(vma, start, end);
  
  			/*
  			 * Try to scan sysctl_numa_balancing_size worth of
  			 * hpages that have at least one present PTE that
  			 * is not already pte-numa. If the VMA contains
  			 * areas that are unused or already full of prot_numa
  			 * PTEs, scan up to virtpages, to skip through those
  			 * areas faster.
  			 */
  			if (nr_pte_updates)
  				pages -= (end - start) >> PAGE_SHIFT;
  			virtpages -= (end - start) >> PAGE_SHIFT;
  
  			start = end;
  			if (pages <= 0 || virtpages <= 0)
  				goto out;
  
  			cond_resched();
  		} while (end != vma->vm_end);
  	}
  
  out:
  	/*
  	 * It is possible to reach the end of the VMA list but the last few
  	 * VMAs are not guaranteed to the vma_migratable. If they are not, we
  	 * would find the !migratable VMA on the next scan but not reset the
  	 * scanner to the start so check it now.
  	 */
  	if (vma)
  		mm->numa_scan_offset = start;
  	else
  		reset_ptenuma_scan(p);
  	up_read(&mm->mmap_sem);
  
  	/*
  	 * Make sure tasks use at least 32x as much time to run other code
  	 * than they used here, to limit NUMA PTE scanning overhead to 3% max.
  	 * Usually update_task_scan_period slows down scanning enough; on an
  	 * overloaded system we need to limit overhead on a per task basis.
  	 */
  	if (unlikely(p->se.sum_exec_runtime != runtime)) {
  		u64 diff = p->se.sum_exec_runtime - runtime;
  		p->node_stamp += 32 * diff;
  	}
  }
  
  /*
   * Drive the periodic memory faults..
   */
  void task_tick_numa(struct rq *rq, struct task_struct *curr)
  {
  	struct callback_head *work = &curr->numa_work;
  	u64 period, now;
  
  	/*
  	 * We don't care about NUMA placement if we don't have memory.
  	 */
  	if (!curr->mm || (curr->flags & PF_EXITING) || work->next != work)
  		return;
  
  	/*
  	 * Using runtime rather than walltime has the dual advantage that
  	 * we (mostly) drive the selection from busy threads and that the
  	 * task needs to have done some actual work before we bother with
  	 * NUMA placement.
  	 */
  	now = curr->se.sum_exec_runtime;
  	period = (u64)curr->numa_scan_period * NSEC_PER_MSEC;
  
  	if (now > curr->node_stamp + period) {
  		if (!curr->node_stamp)
  			curr->numa_scan_period = task_scan_start(curr);
  		curr->node_stamp += period;
  
  		if (!time_before(jiffies, curr->mm->numa_next_scan)) {
  			init_task_work(work, task_numa_work); /* TODO: move this into sched_fork() */
  			task_work_add(curr, work, true);
  		}
  	}
  }
  
  #else
  static void task_tick_numa(struct rq *rq, struct task_struct *curr)
  {
  }
  
  static inline void account_numa_enqueue(struct rq *rq, struct task_struct *p)
  {
  }
  
  static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p)
  {
  }
  
  #endif /* CONFIG_NUMA_BALANCING */
  
  static void
  account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	update_load_add(&cfs_rq->load, se->load.weight);
  	if (!parent_entity(se))
  		update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
  #ifdef CONFIG_SMP
  	if (entity_is_task(se)) {
  		struct rq *rq = rq_of(cfs_rq);
  
  		account_numa_enqueue(rq, task_of(se));
  		list_add(&se->group_node, &rq->cfs_tasks);
  	}
  #endif
  	cfs_rq->nr_running++;
  }
  
  static void
  account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	update_load_sub(&cfs_rq->load, se->load.weight);
  	if (!parent_entity(se))
  		update_load_sub(&rq_of(cfs_rq)->load, se->load.weight);
  #ifdef CONFIG_SMP
  	if (entity_is_task(se)) {
  		account_numa_dequeue(rq_of(cfs_rq), task_of(se));
  		list_del_init(&se->group_node);
  	}
  #endif
  	cfs_rq->nr_running--;
  }
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  # ifdef CONFIG_SMP
  static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
  {
  	long tg_weight, load, shares;
  
  	/*
  	 * This really should be: cfs_rq->avg.load_avg, but instead we use
  	 * cfs_rq->load.weight, which is its upper bound. This helps ramp up
  	 * the shares for small weight interactive tasks.
  	 */
  	load = scale_load_down(cfs_rq->load.weight);
  
  	tg_weight = atomic_long_read(&tg->load_avg);
  
  	/* Ensure tg_weight >= load */
  	tg_weight -= cfs_rq->tg_load_avg_contrib;
  	tg_weight += load;
  
  	shares = (tg->shares * load);
  	if (tg_weight)
  		shares /= tg_weight;
  
  	/*
  	 * MIN_SHARES has to be unscaled here to support per-CPU partitioning
  	 * of a group with small tg->shares value. It is a floor value which is
  	 * assigned as a minimum load.weight to the sched_entity representing
  	 * the group on a CPU.
  	 *
  	 * E.g. on 64-bit for a group with tg->shares of scale_load(15)=15*1024
  	 * on an 8-core system with 8 tasks each runnable on one CPU shares has
  	 * to be 15*1024*1/8=1920 instead of scale_load(MIN_SHARES)=2*1024. In
  	 * case no task is runnable on a CPU MIN_SHARES=2 should be returned
  	 * instead of 0.
  	 */
  	if (shares < MIN_SHARES)
  		shares = MIN_SHARES;
  	if (shares > tg->shares)
  		shares = tg->shares;
  
  	return shares;
  }
  # else /* CONFIG_SMP */
  static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
  {
  	return tg->shares;
  }
  # endif /* CONFIG_SMP */
  
  static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
  			    unsigned long weight)
  {
  	if (se->on_rq) {
  		/* commit outstanding execution time */
  		if (cfs_rq->curr == se)
  			update_curr(cfs_rq);
  		account_entity_dequeue(cfs_rq, se);
  	}
  
  	update_load_set(&se->load, weight);
  
  	if (se->on_rq)
  		account_entity_enqueue(cfs_rq, se);
  }
  
  static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
  
  static void update_cfs_shares(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq = group_cfs_rq(se);
  	struct task_group *tg;
  	long shares;
  
  	if (!cfs_rq)
  		return;
  
  	if (throttled_hierarchy(cfs_rq))
  		return;
  
  	tg = cfs_rq->tg;
  
  #ifndef CONFIG_SMP
  	if (likely(se->load.weight == tg->shares))
  		return;
  #endif
  	shares = calc_cfs_shares(cfs_rq, tg);
  
  	reweight_entity(cfs_rq_of(se), se, shares);
  }
  
  #else /* CONFIG_FAIR_GROUP_SCHED */
  static inline void update_cfs_shares(struct sched_entity *se)
  {
  }
  #endif /* CONFIG_FAIR_GROUP_SCHED */
  
  static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq)
  {
  	struct rq *rq = rq_of(cfs_rq);
  
  #ifdef CONFIG_HISI_CPU_FREQ_GOV_SCHEDUTIL
  	if (!use_pelt_freq())
  		return;
  #endif
  
  	if (&rq->cfs == cfs_rq) {
  		/*
  		 * There are a few boundary cases this might miss but it should
  		 * get called often enough that that should (hopefully) not be
  		 * a real problem -- added to that it only calls on the local
  		 * CPU, so if we enqueue remotely we'll miss an update, but
  		 * the next tick/schedule should update.
  		 *
  		 * It will not get called when we go idle, because the idle
  		 * thread is a different class (!fair), nor will the utilization
  		 * number include things like RT tasks.
  		 *
  		 * As is, the util number is not freq-invariant (we'd have to
  		 * implement arch_scale_freq_capacity() for that).
  		 *
  		 * See cpu_util().
  		 */
  		cpufreq_update_util(rq, 0);
  	}
  }
  
  #ifdef CONFIG_SMP
  /*
   * Approximate:
   *   val * y^n,    where y^32 ~= 0.5 (~1 scheduling period)
   */
  static u64 decay_load(u64 val, u64 n)
  {
  	unsigned int local_n;
  
  	if (unlikely(n > LOAD_AVG_PERIOD * 63))
  		return 0;
  
  	/* after bounds checking we can collapse to 32-bit */
  	local_n = n;
  
  	/*
  	 * As y^PERIOD = 1/2, we can combine
  	 *    y^n = 1/2^(n/PERIOD) * y^(n%PERIOD)
  	 * With a look-up table which covers y^n (n<PERIOD)
  	 *
  	 * To achieve constant time decay_load.
  	 */
  	if (unlikely(local_n >= LOAD_AVG_PERIOD)) {
  		val >>= local_n / LOAD_AVG_PERIOD;
  		local_n %= LOAD_AVG_PERIOD;
  	}
  
  	val = mul_u64_u32_shr(val, runnable_avg_yN_inv[local_n], 32);
  	return val;
  }
  
  static u32 __accumulate_pelt_segments(u64 periods, u32 d1, u32 d3)
  {
  	u32 c1, c2, c3 = d3; /* y^0 == 1 */
  
  	/*
  	 * c1 = d1 y^p
  	 */
  	c1 = decay_load((u64)d1, periods);
  
  	/*
  	 *            p-1
  	 * c2 = 1024 \Sum y^n
  	 *            n=1
  	 *
  	 *              inf        inf
  	 *    = 1024 ( \Sum y^n - \Sum y^n - y^0 )
  	 *              n=0        n=p
  	 */
  	c2 = LOAD_AVG_MAX - decay_load(LOAD_AVG_MAX, periods) - 1024;
  
  	return c1 + c2 + c3;
  }
  
  #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
  
  /*
   * Accumulate the three separate parts of the sum; d1 the remainder
   * of the last (incomplete) period, d2 the span of full periods and d3
   * the remainder of the (incomplete) current period.
   *
   *           d1          d2           d3
   *           ^           ^            ^
   *           |           |            |
   *         |<->|<----------------->|<--->|
   * ... |---x---|------| ... |------|-----x (now)
   *
   *                           p-1
   * u' = (u + d1) y^p + 1024 \Sum y^n + d3 y^0
   *                           n=1
   *
   *    = u y^p +					(Step 1)
   *
   *                     p-1
   *      d1 y^p + 1024 \Sum y^n + d3 y^0		(Step 2)
   *                     n=1
   */
  static __always_inline u32
  accumulate_sum(u64 delta, int cpu, struct sched_avg *sa,
  	       unsigned long weight, int running, struct cfs_rq *cfs_rq)
  {
  	unsigned long scale_freq, scale_cpu;
  	u32 contrib = (u32)delta; /* p == 0 -> delta < 1024 */
  	u64 periods;
  
  	scale_freq = arch_scale_freq_capacity(NULL, cpu);
  	scale_cpu = arch_scale_cpu_capacity(NULL, cpu);
  
  	delta += sa->period_contrib;
  	periods = delta / 1024; /* A period is 1024us (~1ms) */
  
  	/*
  	 * Step 1: decay old *_sum if we crossed period boundaries.
  	 */
  	if (periods) {
  		sa->load_sum = decay_load(sa->load_sum, periods);
  		if (cfs_rq) {
  			cfs_rq->runnable_load_sum =
  				decay_load(cfs_rq->runnable_load_sum, periods);
  		}
  		sa->util_sum = decay_load((u64)(sa->util_sum), periods);
  
  		/*
  		 * Step 2
  		 */
  		delta %= 1024;
  		contrib = __accumulate_pelt_segments(periods,
  				1024 - sa->period_contrib, delta);
  	}
  	sa->period_contrib = delta;
  
  	contrib = cap_scale(contrib, scale_freq);
  	if (weight) {
  		sa->load_sum += weight * contrib;
  		if (cfs_rq)
  			cfs_rq->runnable_load_sum += weight * contrib;
  	}
  	if (running)
  		sa->util_sum += contrib * scale_cpu;
  
  	return periods;
  }
  
  /*
   * We can represent the historical contribution to runnable average as the
   * coefficients of a geometric series.  To do this we sub-divide our runnable
   * history into segments of approximately 1ms (1024us); label the segment that
   * occurred N-ms ago p_N, with p_0 corresponding to the current period, e.g.
   *
   * [<- 1024us ->|<- 1024us ->|<- 1024us ->| ...
   *      p0            p1           p2
   *     (now)       (~1ms ago)  (~2ms ago)
   *
   * Let u_i denote the fraction of p_i that the entity was runnable.
   *
   * We then designate the fractions u_i as our co-efficients, yielding the
   * following representation of historical load:
   *   u_0 + u_1*y + u_2*y^2 + u_3*y^3 + ...
   *
   * We choose y based on the with of a reasonably scheduling period, fixing:
   *   y^32 = 0.5
   *
   * This means that the contribution to load ~32ms ago (u_32) will be weighted
   * approximately half as much as the contribution to load within the last ms
   * (u_0).
   *
   * When a period "rolls over" and we have new u_0`, multiplying the previous
   * sum again by y is sufficient to update:
   *   load_avg = u_0` + y*(u_0 + u_1*y + u_2*y^2 + ... )
   *            = u_0 + u_1*y + u_2*y^2 + ... [re-labeling u_i --> u_{i+1}]
   */
  static __always_inline int
  ___update_load_avg(u64 now, int cpu, struct sched_avg *sa,
  		  unsigned long weight, int running, struct cfs_rq *cfs_rq,
  		  struct rt_rq *rt_rq)
  {
  	u64 delta;
  
  	delta = now - sa->last_update_time;
  	/*
  	 * This should only happen when time goes backwards, which it
  	 * unfortunately does during sched clock init when we swap over to TSC.
  	 */
  	if ((s64)delta < 0) {
  		sa->last_update_time = now;
  		return 0;
  	}
  
  	/*
  	 * Use 1024ns as the unit of measurement since it's a reasonable
  	 * approximation of 1us and fast to compute.
  	 */
  	delta >>= 10;
  	if (!delta)
  		return 0;
  
  	sa->last_update_time += delta << 10;
  
  	/*
  	 * running is a subset of runnable (weight) so running can't be set if
  	 * runnable is clear. But there are some corner cases where the current
  	 * se has been already dequeued but cfs_rq->curr still points to it.
  	 * This means that weight will be 0 but not running for a sched_entity
  	 * but also for a cfs_rq if the latter becomes idle. As an example,
  	 * this happens during idle_balance() which calls
  	 * update_blocked_averages()
  	 */
  	if (!weight)
  		running = 0;
  
  	/*
  	 * Now we know we crossed measurement unit boundaries. The *_avg
  	 * accrues by two steps:
  	 *
  	 * Step 1: accumulate *_sum since last_update_time. If we haven't
  	 * crossed period boundaries, finish.
  	 */
  	if (!accumulate_sum(delta, cpu, sa, weight, running, cfs_rq))
  		return 0;
  
  	/*
  	 * Step 2: update *_avg.
  	 */
  	sa->load_avg = div_u64(sa->load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib);
  	if (cfs_rq) {
  		cfs_rq->runnable_load_avg =
  			div_u64(cfs_rq->runnable_load_sum, LOAD_AVG_MAX - 1024 + sa->period_contrib);
  	}
  	sa->util_avg = sa->util_sum / (LOAD_AVG_MAX - 1024 + sa->period_contrib);
  
  	if (cfs_rq)
  		trace_sched_load_cfs_rq(cfs_rq);
  	else {
  		if (likely(!rt_rq))
  			trace_sched_load_se(container_of(sa, struct sched_entity, avg));
  		else
  			trace_sched_load_rt_rq(cpu, rt_rq);
  	}
  
  	return 1;
  }
  
  /*
   * When a task is dequeued, its estimated utilization should not be update if
   * its util_avg has not been updated at least once.
   * This flag is used to synchronize util_avg updates with util_est updates.
   * We map this information into the LSB bit of the utilization saved at
   * dequeue time (i.e. util_est.dequeued).
   */
  #define UTIL_AVG_UNCHANGED 0x1
  
  static inline void cfs_se_util_change(struct sched_avg *avg)
  {
  	unsigned int enqueued;
  
  	if (!sched_feat(UTIL_EST))
  		return;
  
  	/* Avoid store if the flag has been already set */
  	enqueued = avg->util_est.enqueued;
  	if (!(enqueued & UTIL_AVG_UNCHANGED))
  		return;
  
  	/* Reset flag to report util_avg has been updated */
  	enqueued &= ~UTIL_AVG_UNCHANGED;
  	WRITE_ONCE(avg->util_est.enqueued, enqueued);
  }
  
  static int
  __update_load_avg_blocked_se(u64 now, int cpu, struct sched_entity *se)
  {
  	return ___update_load_avg(now, cpu, &se->avg, 0, 0, NULL, NULL);
  }
  
  static int
  __update_load_avg_se(u64 now, int cpu, struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	if (___update_load_avg(now, cpu, &se->avg,
  			       se->on_rq * scale_load_down(se->load.weight),
  			       cfs_rq->curr == se, NULL, NULL)) {
  		cfs_se_util_change(&se->avg);
  
  #ifdef UTIL_EST_DEBUG
  		/*
  		 * Trace utilization only for actual tasks.
  		 *
  		 * These trace events are mostly useful to get easier to
  		 * read plots for the estimated utilization, where we can
  		 * compare it with the actual grow/decrease of the original
  		 * PELT signal.
  		 * Let's keep them disabled by default in "production kernels".
  		 */
  		if (entity_is_task(se)) {
  			struct task_struct *tsk = task_of(se);
  
  			trace_sched_util_est_task(tsk, &se->avg);
  
  			/* Trace utilization only for top level CFS RQ */
  			cfs_rq = &(task_rq(tsk)->cfs);
  			trace_sched_util_est_cpu(cpu, cfs_rq);
  		}
  #endif /* UTIL_EST_DEBUG */
  
  		return 1;
  	}
  
  	return 0;
  }
  
  static int
  __update_load_avg_cfs_rq(u64 now, int cpu, struct cfs_rq *cfs_rq)
  {
  	return ___update_load_avg(now, cpu, &cfs_rq->avg,
  			scale_load_down(cfs_rq->load.weight),
  			cfs_rq->curr != NULL, cfs_rq, NULL);
  }
  
  /*
   * Signed add and clamp on underflow.
   *
   * Explicitly do a load-store to ensure the intermediate value never hits
   * memory. This allows lockless observations without ever seeing the negative
   * values.
   */
  #define add_positive(_ptr, _val) do {                           \
  	typeof(_ptr) ptr = (_ptr);                              \
  	typeof(_val) val = (_val);                              \
  	typeof(*ptr) res, var = READ_ONCE(*ptr);                \
  								\
  	res = var + val;                                        \
  								\
  	if (val < 0 && res > var)                               \
  		res = 0;                                        \
  								\
  	WRITE_ONCE(*ptr, res);                                  \
  } while (0)
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  /**
   * update_tg_load_avg - update the tg's load avg
   * @cfs_rq: the cfs_rq whose avg changed
   * @force: update regardless of how small the difference
   *
   * This function 'ensures': tg->load_avg := \Sum tg->cfs_rq[]->avg.load.
   * However, because tg->load_avg is a global value there are performance
   * considerations.
   *
   * In order to avoid having to look at the other cfs_rq's, we use a
   * differential update where we store the last value we propagated. This in
   * turn allows skipping updates if the differential is 'small'.
   *
   * Updating tg's load_avg is necessary before update_cfs_share().
   */
  static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force)
  {
  	long delta = cfs_rq->avg.load_avg - cfs_rq->tg_load_avg_contrib;
  
  	/*
  	 * No need to update load_avg for root_task_group as it is not used.
  	 */
  	if (cfs_rq->tg == &root_task_group)
  		return;
  
  	if (force || abs(delta) > cfs_rq->tg_load_avg_contrib / 64) {
  		atomic_long_add(delta, &cfs_rq->tg->load_avg);
  		cfs_rq->tg_load_avg_contrib = cfs_rq->avg.load_avg;
  	}
  
  	trace_sched_load_tg(cfs_rq);
  }
  
  /*
   * Called within set_task_rq() right before setting a task's cpu. The
   * caller only guarantees p->pi_lock is held; no other assumptions,
   * including the state of rq->lock, should be made.
   */
  void set_task_rq_fair(struct sched_entity *se,
  		      struct cfs_rq *prev, struct cfs_rq *next)
  {
  	u64 p_last_update_time;
  	u64 n_last_update_time;
  
  	if (!sched_feat(ATTACH_AGE_LOAD))
  		return;
  
  	/*
  	 * We are supposed to update the task to "current" time, then its up to
  	 * date and ready to go to new CPU/cfs_rq. But we have difficulty in
  	 * getting what current time is, so simply throw away the out-of-date
  	 * time. This will result in the wakee task is less decayed, but giving
  	 * the wakee more load sounds not bad.
  	 */
  	if (!(se->avg.last_update_time && prev))
  		return;
  
  #ifndef CONFIG_64BIT
  	{
  		u64 p_last_update_time_copy;
  		u64 n_last_update_time_copy;
  
  		do {
  			p_last_update_time_copy = prev->load_last_update_time_copy;
  			n_last_update_time_copy = next->load_last_update_time_copy;
  
  			smp_rmb();
  
  			p_last_update_time = prev->avg.last_update_time;
  			n_last_update_time = next->avg.last_update_time;
  
  		} while (p_last_update_time != p_last_update_time_copy ||
  			 n_last_update_time != n_last_update_time_copy);
  	}
  #else
  	p_last_update_time = prev->avg.last_update_time;
  	n_last_update_time = next->avg.last_update_time;
  #endif
  	__update_load_avg_blocked_se(p_last_update_time, cpu_of(rq_of(prev)), se);
  	se->avg.last_update_time = n_last_update_time;
  }
  
  /* Take into account change of utilization of a child task group */
  static inline void
  update_tg_cfs_util(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	struct cfs_rq *gcfs_rq = group_cfs_rq(se);
  	long delta = gcfs_rq->avg.util_avg - se->avg.util_avg;
  
  	/* Nothing to update */
  	if (!delta)
  		return;
  
  	/* Set new sched_entity's utilization */
  	se->avg.util_avg = gcfs_rq->avg.util_avg;
  	se->avg.util_sum = se->avg.util_avg * LOAD_AVG_MAX;
  
  	/* Update parent cfs_rq utilization */
  	add_positive(&cfs_rq->avg.util_avg, delta);
  	cfs_rq->avg.util_sum = cfs_rq->avg.util_avg * LOAD_AVG_MAX;
  }
  
  /* Take into account change of load of a child task group */
  static inline void
  update_tg_cfs_load(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	struct cfs_rq *gcfs_rq = group_cfs_rq(se);
  	long delta, load = gcfs_rq->avg.load_avg;
  
  	/*
  	 * If the load of group cfs_rq is null, the load of the
  	 * sched_entity will also be null so we can skip the formula
  	 */
  	if (load) {
  		long tg_load;
  
  		/* Get tg's load and ensure tg_load > 0 */
  		tg_load = atomic_long_read(&gcfs_rq->tg->load_avg) + 1;
  
  		/* Ensure tg_load >= load and updated with current load*/
  		tg_load -= gcfs_rq->tg_load_avg_contrib;
  		tg_load += load;
  
  		/*
  		 * We need to compute a correction term in the case that the
  		 * task group is consuming more CPU than a task of equal
  		 * weight. A task with a weight equals to tg->shares will have
  		 * a load less or equal to scale_load_down(tg->shares).
  		 * Similarly, the sched_entities that represent the task group
  		 * at parent level, can't have a load higher than
  		 * scale_load_down(tg->shares). And the Sum of sched_entities'
  		 * load must be <= scale_load_down(tg->shares).
  		 */
  		if (tg_load > scale_load_down(gcfs_rq->tg->shares)) {
  			/* scale gcfs_rq's load into tg's shares*/
  			load *= scale_load_down(gcfs_rq->tg->shares);
  			load /= tg_load;
  		}
  	}
  
  	delta = load - se->avg.load_avg;
  
  	/* Nothing to update */
  	if (!delta)
  		return;
  
  	/* Set new sched_entity's load */
  	se->avg.load_avg = load;
  	se->avg.load_sum = se->avg.load_avg * LOAD_AVG_MAX;
  
  	/* Update parent cfs_rq load */
  	add_positive(&cfs_rq->avg.load_avg, delta);
  	cfs_rq->avg.load_sum = cfs_rq->avg.load_avg * LOAD_AVG_MAX;
  
  	/*
  	 * If the sched_entity is already enqueued, we also have to update the
  	 * runnable load avg.
  	 */
  	if (se->on_rq) {
  		/* Update parent cfs_rq runnable_load_avg */
  		add_positive(&cfs_rq->runnable_load_avg, delta);
  		cfs_rq->runnable_load_sum = cfs_rq->runnable_load_avg * LOAD_AVG_MAX;
  	}
  }
  
  static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq)
  {
  	cfs_rq->propagate_avg = 1;
  }
  
  static inline int test_and_clear_tg_cfs_propagate(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq = group_cfs_rq(se);
  
  	if (!cfs_rq->propagate_avg)
  		return 0;
  
  	cfs_rq->propagate_avg = 0;
  	return 1;
  }
  
  /* Update task and its cfs_rq load average */
  static inline int propagate_entity_load_avg(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq;
  
  	if (entity_is_task(se))
  		return 0;
  
  	if (!test_and_clear_tg_cfs_propagate(se))
  		return 0;
  
  	cfs_rq = cfs_rq_of(se);
  
  	set_tg_cfs_propagate(cfs_rq);
  
  	update_tg_cfs_util(cfs_rq, se);
  	update_tg_cfs_load(cfs_rq, se);
  
  	trace_sched_load_cfs_rq(cfs_rq);
  	trace_sched_load_se(se);
  
  	return 1;
  }
  
  /*
   * Check if we need to update the load and the utilization of a blocked
   * group_entity:
   */
  static inline bool skip_blocked_update(struct sched_entity *se)
  {
  	struct cfs_rq *gcfs_rq = group_cfs_rq(se);
  
  	/*
  	 * If sched_entity still have not zero load or utilization, we have to
  	 * decay it:
  	 */
  	if (se->avg.load_avg || se->avg.util_avg)
  		return false;
  
  	/*
  	 * If there is a pending propagation, we have to update the load and
  	 * the utilization of the sched_entity:
  	 */
  	if (gcfs_rq->propagate_avg)
  		return false;
  
  	/*
  	 * Otherwise, the load and the utilization of the sched_entity is
  	 * already zero and there is no pending propagation, so it will be a
  	 * waste of time to try to decay it:
  	 */
  	return true;
  }
  
  #else /* CONFIG_FAIR_GROUP_SCHED */
  
  static inline void update_tg_load_avg(struct cfs_rq *cfs_rq, int force) {}
  
  static inline int propagate_entity_load_avg(struct sched_entity *se)
  {
  	return 0;
  }
  
  static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq) {}
  
  #endif /* CONFIG_FAIR_GROUP_SCHED */
  
  /*
   * Unsigned subtract and clamp on underflow.
   *
   * Explicitly do a load-store to ensure the intermediate value never hits
   * memory. This allows lockless observations without ever seeing the negative
   * values.
   */
  #define sub_positive(_ptr, _val) do {				\
  	typeof(_ptr) ptr = (_ptr);				\
  	typeof(*ptr) val = (_val);				\
  	typeof(*ptr) res, var = READ_ONCE(*ptr);		\
  	res = var - val;					\
  	if (res > var)						\
  		res = 0;					\
  	WRITE_ONCE(*ptr, res);					\
  } while (0)
  
  /**
   * update_cfs_rq_load_avg - update the cfs_rq's load/util averages
   * @now: current time, as per cfs_rq_clock_task()
   * @cfs_rq: cfs_rq to update
   *
   * The cfs_rq avg is the direct sum of all its entities (blocked and runnable)
   * avg. The immediate corollary is that all (fair) tasks must be attached, see
   * post_init_entity_util_avg().
   *
   * cfs_rq->avg is used for task_h_load() and update_cfs_share() for example.
   *
   * Returns true if the load decayed or we removed load.
   *
   * Since both these conditions indicate a changed cfs_rq->avg.load we should
   * call update_tg_load_avg() when this function returns true.
   */
  static inline int
  update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
  {
  	struct sched_avg *sa = &cfs_rq->avg;
  	int decayed, removed_load = 0, removed_util = 0;
  
  	if (atomic_long_read(&cfs_rq->removed_load_avg)) {
  		s64 r = atomic_long_xchg(&cfs_rq->removed_load_avg, 0);
  		sub_positive(&sa->load_avg, r);
  		sub_positive(&sa->load_sum, r * LOAD_AVG_MAX);
  		removed_load = 1;
  		set_tg_cfs_propagate(cfs_rq);
  	}
  
  	if (atomic_long_read(&cfs_rq->removed_util_avg)) {
  		long r = atomic_long_xchg(&cfs_rq->removed_util_avg, 0);
  		sub_positive(&sa->util_avg, r);
  		sub_positive(&sa->util_sum, r * LOAD_AVG_MAX);
  		removed_util = 1;
  		set_tg_cfs_propagate(cfs_rq);
  	}
  
  	decayed = __update_load_avg_cfs_rq(now, cpu_of(rq_of(cfs_rq)), cfs_rq);
  
  #ifndef CONFIG_64BIT
  	smp_wmb();
  	cfs_rq->load_last_update_time_copy = sa->last_update_time;
  #endif
  
  	if (decayed || removed_util)
  		cfs_rq_util_change(cfs_rq);
  
  	return decayed || removed_load;
  }
  
  int update_rt_rq_load_avg(u64 now, int cpu, struct rt_rq *rt_rq, int running)
  {
  	int ret;
  
  	ret = ___update_load_avg(now, cpu, &rt_rq->avg, 0, running, NULL, rt_rq);
  
  	return ret;
  }
  
  /*
   * Optional action to be done while updating the load average
   */
  #define UPDATE_TG	0x1
  #define SKIP_AGE_LOAD	0x2
  
  /* Update task and its cfs_rq load average */
  static inline void update_load_avg(struct sched_entity *se, int flags)
  {
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  	u64 now = cfs_rq_clock_task(cfs_rq);
  	struct rq *rq = rq_of(cfs_rq);
  	int cpu = cpu_of(rq);
  	int decayed;
  
  	/*
  	 * Track task load average for carrying it to new CPU after migrated, and
  	 * track group sched_entity load average for task_h_load calc in migration
  	 */
  	if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD))
  		__update_load_avg_se(now, cpu, cfs_rq, se);
  
  	decayed  = update_cfs_rq_load_avg(now, cfs_rq);
  	decayed |= propagate_entity_load_avg(se);
  
  	if (decayed && (flags & UPDATE_TG))
  		update_tg_load_avg(cfs_rq, 0);
  }
  
  /**
   * attach_entity_load_avg - attach this entity to its cfs_rq load avg
   * @cfs_rq: cfs_rq to attach to
   * @se: sched_entity to attach
   *
   * Must call update_cfs_rq_load_avg() before this, since we rely on
   * cfs_rq->avg.last_update_time being current.
   */
  static void attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	se->avg.last_update_time = cfs_rq->avg.last_update_time;
  	cfs_rq->avg.load_avg += se->avg.load_avg;
  	cfs_rq->avg.load_sum += se->avg.load_sum;
  	cfs_rq->avg.util_avg += se->avg.util_avg;
  	cfs_rq->avg.util_sum += se->avg.util_sum;
  	set_tg_cfs_propagate(cfs_rq);
  
  	cfs_rq_util_change(cfs_rq);
  
  	trace_sched_load_cfs_rq(cfs_rq);
  }
  
  /**
   * detach_entity_load_avg - detach this entity from its cfs_rq load avg
   * @cfs_rq: cfs_rq to detach from
   * @se: sched_entity to detach
   *
   * Must call update_cfs_rq_load_avg() before this, since we rely on
   * cfs_rq->avg.last_update_time being current.
   */
  static void detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  
  	sub_positive(&cfs_rq->avg.load_avg, se->avg.load_avg);
  	sub_positive(&cfs_rq->avg.load_sum, se->avg.load_sum);
  	sub_positive(&cfs_rq->avg.util_avg, se->avg.util_avg);
  	sub_positive(&cfs_rq->avg.util_sum, se->avg.util_sum);
  	set_tg_cfs_propagate(cfs_rq);
  
  	cfs_rq_util_change(cfs_rq);
  
  	trace_sched_load_cfs_rq(cfs_rq);
  }
  
  /* Add the load generated by se into cfs_rq's load average */
  static inline void
  enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	struct sched_avg *sa = &se->avg;
  
  	cfs_rq->runnable_load_avg += sa->load_avg;
  	cfs_rq->runnable_load_sum += sa->load_sum;
  
  	if (!sa->last_update_time) {
  		attach_entity_load_avg(cfs_rq, se);
  		update_tg_load_avg(cfs_rq, 0);
  	}
  }
  
  /* Remove the runnable load generated by se from cfs_rq's runnable load average */
  static inline void
  dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	cfs_rq->runnable_load_avg =
  		max_t(long, cfs_rq->runnable_load_avg - se->avg.load_avg, 0);
  	cfs_rq->runnable_load_sum =
  		max_t(s64,  cfs_rq->runnable_load_sum - se->avg.load_sum, 0);
  }
  
  #ifndef CONFIG_64BIT
  static inline u64 cfs_rq_last_update_time(struct cfs_rq *cfs_rq)
  {
  	u64 last_update_time_copy;
  	u64 last_update_time;
  
  	do {
  		last_update_time_copy = cfs_rq->load_last_update_time_copy;
  		smp_rmb();
  		last_update_time = cfs_rq->avg.last_update_time;
  	} while (last_update_time != last_update_time_copy);
  
  	return last_update_time;
  }
  #else
  static inline u64 cfs_rq_last_update_time(struct cfs_rq *cfs_rq)
  {
  	return cfs_rq->avg.last_update_time;
  }
  #endif
  
  /*
   * Synchronize entity load avg of dequeued entity without locking
   * the previous rq.
   */
  void sync_entity_load_avg(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  	u64 last_update_time;
  
  	last_update_time = cfs_rq_last_update_time(cfs_rq);
  	__update_load_avg_blocked_se(last_update_time, cpu_of(rq_of(cfs_rq)), se);
  }
  
  /*
   * Task first catches up with cfs_rq, and then subtract
   * itself from the cfs_rq (task must be off the queue now).
   */
  void remove_entity_load_avg(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  
  	/*
  	 * tasks cannot exit without having gone through wake_up_new_task() ->
  	 * post_init_entity_util_avg() which will have added things to the
  	 * cfs_rq, so we can remove unconditionally.
  	 *
  	 * Similarly for groups, they will have passed through
  	 * post_init_entity_util_avg() before unregister_sched_fair_group()
  	 * calls this.
  	 */
  
  	sync_entity_load_avg(se);
  	atomic_long_add(se->avg.load_avg, &cfs_rq->removed_load_avg);
  	atomic_long_add(se->avg.util_avg, &cfs_rq->removed_util_avg);
  }
  
  static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq)
  {
  	return cfs_rq->runnable_load_avg;
  }
  
  static inline unsigned long cfs_rq_load_avg(struct cfs_rq *cfs_rq)
  {
  	return cfs_rq->avg.load_avg;
  }
  
  static int idle_balance(struct rq *this_rq, struct rq_flags *rf);
  
  #ifdef CONFIG_HISI_EAS_SCHED
  static inline bool task_fits_max(struct task_struct *p, int cpu);
  #else
  static inline int task_fits_capacity(struct task_struct *p, long capacity);
  #endif
  
  #ifdef CONFIG_HISI_RTG
  static inline bool is_rtg_task(struct task_struct *p)
  {
  	struct related_thread_group *grp = NULL;
  	bool is_rtg = false;
  
  	rcu_read_lock();
  	grp = task_related_thread_group(p);
  	is_rtg = grp && grp->preferred_cluster;
  	rcu_read_unlock();
  
  	return is_rtg;
  }
  
  static inline bool rtg_task_misfit(struct task_struct *p, int cpu)
  {
  	struct related_thread_group *grp = NULL;
  	bool misfit = false;
  
  	rcu_read_lock();
  
  	grp = task_related_thread_group(p);
  	if (!grp || !grp->preferred_cluster)
  		goto out;
  
  	if (capacity_orig_of(cpumask_first(&grp->preferred_cluster->cpus)) >
  	    capacity_orig_of(cpu))
  		misfit = true;
  
  out:
  	rcu_read_unlock();
  
  	return misfit;
  }
  #else
  static inline bool is_rtg_task(struct task_struct *p)
  {
  	return false;
  }
  static inline bool rtg_task_misfit(struct task_struct *p, int cpu)
  {
  	return false;
  }
  #endif
  
  static inline void update_misfit_status(struct task_struct *p, struct rq *rq)
  {
  #ifdef CONFIG_HISI_EAS_SCHED
  	bool task_fits = false;
  	int cpu = cpu_of(rq);
  #else
  	if (!static_branch_unlikely(&sched_asym_cpucapacity))
  		return;
  #endif
  
  	if (!p) {
  		rq->misfit_task_load = 0;
  		return;
  	}
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	task_fits = is_rtg_task(p)
  		? !rtg_task_misfit(p, cpu)
  		: task_fits_max(p, cpu);
  
  	if (task_fits) {
  #else
  	if (task_fits_capacity(p, capacity_of(cpu_of(rq)))) {
  #endif
  		rq->misfit_task_load = 0;
  		return;
  	}
  
  	rq->misfit_task_load = task_h_load(p);
  }
  
  #ifdef CONFIG_HISI_EAS_SCHED
  unsigned int sysctl_sched_force_upmigrate_duration = 50000000; /* 50 ms */
  
  static inline void
  check_force_upmigrate(struct task_struct *p, struct rq *rq)
  {
  	unsigned long capacity_orig;
  	int cpu;
  
  	if (!render_rt_inited())
  		return;
  
  	capacity_orig = capacity_orig_of(cpu_of(rq));
  	if (capacity_orig == rq->rd->max_cpu_capacity.val)
  		return;
  
  	if (rq->misfit_task_load)
  		return;
  
  	if (likely(walt_ktime_clock() - p->last_enqueued_ts <
  			sysctl_sched_force_upmigrate_duration))
  		return;
  
  	for_each_cpu_and(cpu, &p->cpus_allowed, cpu_online_mask) {
  		if (capacity_orig_of(cpu) > capacity_orig) {
  			/* Suitable for upmigration. Mark it misfit. */
  			rq->misfit_task_load = task_h_load(p);
  			return;
  		}
  	}
  }
  #endif
  
  unsigned long task_util(struct task_struct *p)
  {
  #ifdef CONFIG_SCHED_WALT
  	if (likely(!walt_disabled && sysctl_sched_use_walt_task_util))
  		return (p->ravg.demand /
  			(walt_ravg_window >> SCHED_CAPACITY_SHIFT));
  #endif
  	return READ_ONCE(p->se.avg.util_avg);
  }
  
  static inline unsigned long _task_util_est(struct task_struct *p)
  {
  	struct util_est ue = READ_ONCE(p->se.avg.util_est);
  
  	return max(ue.ewma, ue.enqueued);
  }
  
  static inline unsigned long task_util_est(struct task_struct *p)
  {
  #ifdef CONFIG_SCHED_WALT
  	if (likely(!walt_disabled && sysctl_sched_use_walt_task_util))
  		return (p->ravg.demand /
  			(walt_ravg_window >> SCHED_CAPACITY_SHIFT));
  #endif
  	return max(task_util(p), _task_util_est(p));
  }
  
  static inline void util_est_enqueue(struct cfs_rq *cfs_rq,
  				    struct task_struct *p)
  {
  	unsigned int enqueued;
  
  	if (!sched_feat(UTIL_EST))
  		return;
  
  	/* Update root cfs_rq's estimated utilization */
  	enqueued  = cfs_rq->avg.util_est.enqueued;
  	enqueued += (_task_util_est(p) | UTIL_AVG_UNCHANGED);
  	WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued);
  
  	trace_sched_util_est_task(p, &p->se.avg);
  	trace_sched_util_est_cpu(cpu_of(rq_of(cfs_rq)), cfs_rq);
  }
  
  /*
   * Check if a (signed) value is within a specified (unsigned) margin,
   * based on the observation that:
   *
   *     abs(x) < y := (unsigned)(x + y - 1) < (2 * y - 1)
   *
   * NOTE: this only works when value + maring < INT_MAX.
   */
  static inline bool within_margin(int value, int margin)
  {
  	return ((unsigned int)(value + margin - 1) < (2 * margin - 1));
  }
  
  static void
  util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
  {
  	long last_ewma_diff;
  	struct util_est ue;
  
  	if (!sched_feat(UTIL_EST))
  		return;
  
  	/*
  	 * Update root cfs_rq's estimated utilization
  	 *
  	 * If *p is the last task then the root cfs_rq's estimated utilization
  	 * of a CPU is 0 by definition.
  	 */
  	ue.enqueued = 0;
  	if (cfs_rq->nr_running) {
  		ue.enqueued  = cfs_rq->avg.util_est.enqueued;
  		ue.enqueued -= min_t(unsigned int, ue.enqueued,
  				     (_task_util_est(p) | UTIL_AVG_UNCHANGED));
  	}
  	WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued);
  
  	trace_sched_util_est_cpu(cpu_of(rq_of(cfs_rq)), cfs_rq);
  
  	/*
  	 * Skip update of task's estimated utilization when the task has not
  	 * yet completed an activation, e.g. being migrated.
  	 */
  	if (!task_sleep)
  		return;
  
  	/*
  	 * If the PELT values haven't changed since enqueue time,
  	 * skip the util_est update.
  	 */
  	ue = p->se.avg.util_est;
  	if (ue.enqueued & UTIL_AVG_UNCHANGED)
  		return;
  
  	/*
  	 * Skip update of task's estimated utilization when its EWMA is
  	 * already ~1% close to its last activation value.
  	 */
  	ue.enqueued = (task_util(p) | UTIL_AVG_UNCHANGED);
  	last_ewma_diff = ue.enqueued - ue.ewma;
  	if (within_margin(last_ewma_diff, (SCHED_CAPACITY_SCALE / 100)))
  		return;
  
  	/*
  	 * Update Task's estimated utilization
  	 *
  	 * When *p completes an activation we can consolidate another sample
  	 * of the task size. This is done by storing the current PELT value
  	 * as ue.enqueued and by using this value to update the Exponential
  	 * Weighted Moving Average (EWMA):
  	 *
  	 *  ewma(t) = w *  task_util(p) + (1-w) * ewma(t-1)
  	 *          = w *  task_util(p) +         ewma(t-1)  - w * ewma(t-1)
  	 *          = w * (task_util(p) -         ewma(t-1)) +     ewma(t-1)
  	 *          = w * (      last_ewma_diff            ) +     ewma(t-1)
  	 *          = w * (last_ewma_diff  +  ewma(t-1) / w)
  	 *
  	 * Where 'w' is the weight of new samples, which is configured to be
  	 * 0.25, thus making w=1/4 ( >>= UTIL_EST_WEIGHT_SHIFT)
  	 */
  	ue.ewma <<= UTIL_EST_WEIGHT_SHIFT;
  	ue.ewma  += last_ewma_diff;
  	ue.ewma >>= UTIL_EST_WEIGHT_SHIFT;
  	WRITE_ONCE(p->se.avg.util_est, ue);
  
  	trace_sched_util_est_task(p, &p->se.avg);
  }
  
  #else /* CONFIG_SMP */
  
  static inline int
  update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
  {
  	return 0;
  }
  
  int update_rt_rq_load_avg(u64 now, int cpu, struct rt_rq *rt_rq, int running)
  {
  	return 0;
  }
  
  #define UPDATE_TG	0x0
  #define SKIP_AGE_LOAD	0x0
  
  static inline void update_load_avg(struct sched_entity *se, int not_used1)
  {
  	cfs_rq_util_change(cfs_rq_of(se));
  }
  
  static inline void
  enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
  static inline void
  dequeue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
  static inline void remove_entity_load_avg(struct sched_entity *se) {}
  
  static inline void
  attach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
  static inline void
  detach_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) {}
  
  static inline int idle_balance(struct rq *rq, struct rq_flags *rf)
  {
  	return 0;
  }
  
  static inline void update_misfit_status(struct task_struct *p, struct rq *rq) {}
  
  static inline void
  util_est_enqueue(struct cfs_rq *cfs_rq, struct task_struct *p) {}
  
  static inline void
  util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p,
  		 bool task_sleep) {}
  
  #endif /* CONFIG_SMP */
  
  static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  #ifdef CONFIG_SCHED_DEBUG
  	s64 d = se->vruntime - cfs_rq->min_vruntime;
  
  	if (d < 0)
  		d = -d;
  
  	if (d > 3*sysctl_sched_latency)
  		schedstat_inc(cfs_rq->nr_spread_over);
  #endif
  }
  
  static void
  place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
  {
  	u64 vruntime = cfs_rq->min_vruntime;
  
  	/*
  	 * The 'current' period is already promised to the current tasks,
  	 * however the extra weight of the new task will slow them down a
  	 * little, place the new task so that it fits in the slot that
  	 * stays open at the end.
  	 */
  	if (initial && sched_feat(START_DEBIT))
  		vruntime += sched_vslice(cfs_rq, se);
  
  	/* sleeps up to a single latency don't count. */
  	if (!initial) {
  		unsigned long thresh = sysctl_sched_latency;
  
  		/*
  		 * Halve their sleep time's effect, to allow
  		 * for a gentler effect of sleepers:
  		 */
  		if (sched_feat(GENTLE_FAIR_SLEEPERS))
  			thresh >>= 1;
  
  		vruntime -= thresh;
  	}
  
  	/* ensure we never gain time by being placed backwards. */
  	se->vruntime = max_vruntime(se->vruntime, vruntime);
  }
  
  static void check_enqueue_throttle(struct cfs_rq *cfs_rq);
  
  static inline void check_schedstat_required(void)
  {
  #ifdef CONFIG_SCHEDSTATS
  	if (schedstat_enabled())
  		return;
  
  	/* Force schedstat enabled if a dependent tracepoint is active */
  	if (trace_sched_stat_wait_enabled()    ||
  			trace_sched_stat_sleep_enabled()   ||
  			trace_sched_stat_iowait_enabled()  ||
  			trace_sched_stat_blocked_enabled() ||
  			trace_sched_stat_runtime_enabled())  {
  		printk_deferred_once("Scheduler tracepoints stat_sleep, stat_iowait, "
  			     "stat_blocked and stat_runtime require the "
  			     "kernel parameter schedstats=enable or "
  			     "kernel.sched_schedstats=1\n");
  	}
  #endif
  }
  
  
  /*
   * MIGRATION
   *
   *	dequeue
   *	  update_curr()
   *	    update_min_vruntime()
   *	  vruntime -= min_vruntime
   *
   *	enqueue
   *	  update_curr()
   *	    update_min_vruntime()
   *	  vruntime += min_vruntime
   *
   * this way the vruntime transition between RQs is done when both
   * min_vruntime are up-to-date.
   *
   * WAKEUP (remote)
   *
   *	->migrate_task_rq_fair() (p->state == TASK_WAKING)
   *	  vruntime -= min_vruntime
   *
   *	enqueue
   *	  update_curr()
   *	    update_min_vruntime()
   *	  vruntime += min_vruntime
   *
   * this way we don't have the most up-to-date min_vruntime on the originating
   * CPU and an up-to-date min_vruntime on the destination CPU.
   */
  
  static void
  enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
  {
  	bool renorm = !(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_MIGRATED);
  	bool curr = cfs_rq->curr == se;
  
  	/*
  	 * If we're the current task, we must renormalise before calling
  	 * update_curr().
  	 */
  	if (renorm && curr)
  		se->vruntime += cfs_rq->min_vruntime;
  
  	update_curr(cfs_rq);
  
  	/*
  	 * Otherwise, renormalise after, such that we're placed at the current
  	 * moment in time, instead of some random moment in the past. Being
  	 * placed in the past could significantly boost this task to the
  	 * fairness detriment of existing tasks.
  	 */
  	if (renorm && !curr)
  		se->vruntime += cfs_rq->min_vruntime;
  
  	/*
  	 * When enqueuing a sched_entity, we must:
  	 *   - Update loads to have both entity and cfs_rq synced with now.
  	 *   - Add its load to cfs_rq->runnable_avg
  	 *   - For group_entity, update its weight to reflect the new share of
  	 *     its group cfs_rq
  	 *   - Add its new weight to cfs_rq->load.weight
  	 */
  	update_load_avg(se, UPDATE_TG);
  	enqueue_entity_load_avg(cfs_rq, se);
  	update_cfs_shares(se);
  	account_entity_enqueue(cfs_rq, se);
  
  	if (flags & ENQUEUE_WAKEUP)
  		place_entity(cfs_rq, se, 0);
  
  	check_schedstat_required();
  	update_stats_enqueue(cfs_rq, se, flags);
  	check_spread(cfs_rq, se);
  	if (!curr)
  		__enqueue_entity(cfs_rq, se);
  	se->on_rq = 1;
  
  	if (cfs_rq->nr_running == 1) {
  		list_add_leaf_cfs_rq(cfs_rq);
  		check_enqueue_throttle(cfs_rq);
  	}
  }
  
  static void __clear_buddies_last(struct sched_entity *se)
  {
  	for_each_sched_entity(se) {
  		struct cfs_rq *cfs_rq = cfs_rq_of(se);
  		if (cfs_rq->last != se)
  			break;
  
  		cfs_rq->last = NULL;
  	}
  }
  
  static void __clear_buddies_next(struct sched_entity *se)
  {
  	for_each_sched_entity(se) {
  		struct cfs_rq *cfs_rq = cfs_rq_of(se);
  		if (cfs_rq->next != se)
  			break;
  
  		cfs_rq->next = NULL;
  	}
  }
  
  static void __clear_buddies_skip(struct sched_entity *se)
  {
  	for_each_sched_entity(se) {
  		struct cfs_rq *cfs_rq = cfs_rq_of(se);
  		if (cfs_rq->skip != se)
  			break;
  
  		cfs_rq->skip = NULL;
  	}
  }
  
  static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	if (cfs_rq->last == se)
  		__clear_buddies_last(se);
  
  	if (cfs_rq->next == se)
  		__clear_buddies_next(se);
  
  	if (cfs_rq->skip == se)
  		__clear_buddies_skip(se);
  }
  
  static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq);
  
  static void
  dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
  {
  	/*
  	 * Update run-time statistics of the 'current'.
  	 */
  	update_curr(cfs_rq);
  
  	/*
  	 * When dequeuing a sched_entity, we must:
  	 *   - Update loads to have both entity and cfs_rq synced with now.
  	 *   - Substract its load from the cfs_rq->runnable_avg.
  	 *   - Substract its previous weight from cfs_rq->load.weight.
  	 *   - For group entity, update its weight to reflect the new share
  	 *     of its group cfs_rq.
  	 */
  	update_load_avg(se, UPDATE_TG);
  	dequeue_entity_load_avg(cfs_rq, se);
  
  	update_stats_dequeue(cfs_rq, se, flags);
  
  	clear_buddies(cfs_rq, se);
  
  	if (se != cfs_rq->curr)
  		__dequeue_entity(cfs_rq, se);
  	se->on_rq = 0;
  	account_entity_dequeue(cfs_rq, se);
  
  	/*
  	 * Normalize after update_curr(); which will also have moved
  	 * min_vruntime if @se is the one holding it back. But before doing
  	 * update_min_vruntime() again, which will discount @se's position and
  	 * can move min_vruntime forward still more.
  	 */
  	if (!(flags & DEQUEUE_SLEEP))
  		se->vruntime -= cfs_rq->min_vruntime;
  
  	/* return excess runtime on last dequeue */
  	return_cfs_rq_runtime(cfs_rq);
  
  	update_cfs_shares(se);
  
  	/*
  	 * Now advance min_vruntime if @se was the entity holding it back,
  	 * except when: DEQUEUE_SAVE && !DEQUEUE_MOVE, in this case we'll be
  	 * put back on, and if we advance min_vruntime, we'll be placed back
  	 * further than we started -- ie. we'll be penalized.
  	 */
  	if ((flags & (DEQUEUE_SAVE | DEQUEUE_MOVE)) != DEQUEUE_SAVE)
  		update_min_vruntime(cfs_rq);
  }
  
  /*
   * Preempt the current task with a newly woken task if needed:
   */
  static void
  check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
  {
  	unsigned long ideal_runtime, delta_exec;
  	struct sched_entity *se;
  	s64 delta;
  
  	ideal_runtime = sched_slice(cfs_rq, curr);
  	delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
  	if (delta_exec > ideal_runtime) {
  		resched_curr(rq_of(cfs_rq));
  		/*
  		 * The current task ran long enough, ensure it doesn't get
  		 * re-elected due to buddy favours.
  		 */
  		clear_buddies(cfs_rq, curr);
  		return;
  	}
  
  	/*
  	 * Ensure that a task that missed wakeup preemption by a
  	 * narrow margin doesn't have to wait for a full slice.
  	 * This also mitigates buddy induced latencies under load.
  	 */
  	if (delta_exec < sysctl_sched_min_granularity)
  		return;
  
  	se = __pick_first_entity(cfs_rq);
  	delta = curr->vruntime - se->vruntime;
  
  	if (delta < 0)
  		return;
  
  	if (delta > ideal_runtime)
  		resched_curr(rq_of(cfs_rq));
  }
  
  static void
  set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
  {
  	/* 'current' is not kept within the tree. */
  	if (se->on_rq) {
  		/*
  		 * Any task has to be enqueued before it get to execute on
  		 * a CPU. So account for the time it spent waiting on the
  		 * runqueue.
  		 */
  		update_stats_wait_end(cfs_rq, se);
  		__dequeue_entity(cfs_rq, se);
  		update_load_avg(se, UPDATE_TG);
  	}
  
  	update_stats_curr_start(cfs_rq, se);
  	cfs_rq->curr = se;
  
  	/*
  	 * Track our maximum slice length, if the CPU's load is at
  	 * least twice that of our own weight (i.e. dont track it
  	 * when there are only lesser-weight tasks around):
  	 */
  	if (schedstat_enabled() && rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
  		schedstat_set(se->statistics.slice_max,
  			max((u64)schedstat_val(se->statistics.slice_max),
  			    se->sum_exec_runtime - se->prev_sum_exec_runtime));
  	}
  
  	se->prev_sum_exec_runtime = se->sum_exec_runtime;
  }
  
  static int
  wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
  
  /*
   * Pick the next process, keeping these things in mind, in this order:
   * 1) keep things fair between processes/task groups
   * 2) pick the "next" process, since someone really wants that to run
   * 3) pick the "last" process, for cache locality
   * 4) do not run the "skip" process, if something else is available
   */
  static struct sched_entity *
  pick_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *curr)
  {
  	struct sched_entity *left = __pick_first_entity(cfs_rq);
  	struct sched_entity *se;
  
  	/*
  	 * If curr is set we have to see if its left of the leftmost entity
  	 * still in the tree, provided there was anything in the tree at all.
  	 */
  	if (!left || (curr && entity_before(curr, left)))
  		left = curr;
  
  	se = left; /* ideally we run the leftmost entity */
  
  	/*
  	 * Avoid running the skip buddy, if running something else can
  	 * be done without getting too unfair.
  	 */
  	if (cfs_rq->skip == se) {
  		struct sched_entity *second;
  
  		if (se == curr) {
  			second = __pick_first_entity(cfs_rq);
  		} else {
  			second = __pick_next_entity(se);
  			if (!second || (curr && entity_before(curr, second)))
  				second = curr;
  		}
  
  		if (second && wakeup_preempt_entity(second, left) < 1)
  			se = second;
  	}
  
  	/*
  	 * Prefer last buddy, try to return the CPU to a preempted task.
  	 */
  	if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1)
  		se = cfs_rq->last;
  
  	/*
  	 * Someone really wants this to run. If it's not unfair, run it.
  	 */
  	if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1)
  		se = cfs_rq->next;
  
  	clear_buddies(cfs_rq, se);
  
  	return se;
  }
  
  static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq);
  
  static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
  {
  	/*
  	 * If still on the runqueue then deactivate_task()
  	 * was not called and update_curr() has to be done:
  	 */
  	if (prev->on_rq)
  		update_curr(cfs_rq);
  
  	/* throttle cfs_rqs exceeding runtime */
  	check_cfs_rq_runtime(cfs_rq);
  
  	check_spread(cfs_rq, prev);
  
  	if (prev->on_rq) {
  		update_stats_wait_start(cfs_rq, prev);
  		/* Put 'current' back into the tree. */
  		__enqueue_entity(cfs_rq, prev);
  		/* in !on_rq case, update occurred at dequeue */
  		update_load_avg(prev, 0);
  	}
  	cfs_rq->curr = NULL;
  }
  
  static void
  entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
  {
  	/*
  	 * Update run-time statistics of the 'current'.
  	 */
  	update_curr(cfs_rq);
  
  	/*
  	 * Ensure that runnable average is periodically updated.
  	 */
  	update_load_avg(curr, UPDATE_TG);
  	update_cfs_shares(curr);
  
  #ifdef CONFIG_SCHED_HRTICK
  	/*
  	 * queued ticks are scheduled to match the slice, so don't bother
  	 * validating it and just reschedule.
  	 */
  	if (queued) {
  		resched_curr(rq_of(cfs_rq));
  		return;
  	}
  	/*
  	 * don't let the period tick interfere with the hrtick preemption
  	 */
  	if (!sched_feat(DOUBLE_TICK) &&
  			hrtimer_active(&rq_of(cfs_rq)->hrtick_timer))
  		return;
  #endif
  
  	if (cfs_rq->nr_running > 1)
  		check_preempt_tick(cfs_rq, curr);
  }
  
  
  /**************************************************
   * CFS bandwidth control machinery
   */
  
  #ifdef CONFIG_CFS_BANDWIDTH
  
  #ifdef HAVE_JUMP_LABEL
  static struct static_key __cfs_bandwidth_used;
  
  static inline bool cfs_bandwidth_used(void)
  {
  	return static_key_false(&__cfs_bandwidth_used);
  }
  
  void cfs_bandwidth_usage_inc(void)
  {
  	static_key_slow_inc_cpuslocked(&__cfs_bandwidth_used);
  }
  
  void cfs_bandwidth_usage_dec(void)
  {
  	static_key_slow_dec_cpuslocked(&__cfs_bandwidth_used);
  }
  #else /* HAVE_JUMP_LABEL */
  static bool cfs_bandwidth_used(void)
  {
  	return true;
  }
  
  void cfs_bandwidth_usage_inc(void) {}
  void cfs_bandwidth_usage_dec(void) {}
  #endif /* HAVE_JUMP_LABEL */
  
  /*
   * default period for cfs group bandwidth.
   * default: 0.1s, units: nanoseconds
   */
  static inline u64 default_cfs_period(void)
  {
  	return 100000000ULL;
  }
  
  static inline u64 sched_cfs_bandwidth_slice(void)
  {
  	return (u64)sysctl_sched_cfs_bandwidth_slice * NSEC_PER_USEC;
  }
  
  /*
   * Replenish runtime according to assigned quota. We use sched_clock_cpu
   * directly instead of rq->clock to avoid adding additional synchronization
   * around rq->lock.
   *
   * requires cfs_b->lock
   */
  void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b)
  {
  	if (cfs_b->quota != RUNTIME_INF)
  		cfs_b->runtime = cfs_b->quota;
  }
  
  static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
  {
  	return &tg->cfs_bandwidth;
  }
  
  /* rq->task_clock normalized against any time this cfs_rq has spent throttled */
  static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq)
  {
  	if (unlikely(cfs_rq->throttle_count))
  		return cfs_rq->throttled_clock_task - cfs_rq->throttled_clock_task_time;
  
  	return rq_clock_task(rq_of(cfs_rq)) - cfs_rq->throttled_clock_task_time;
  }
  
  /* returns 0 on failure to allocate runtime */
  static int assign_cfs_rq_runtime(struct cfs_rq *cfs_rq)
  {
  	struct task_group *tg = cfs_rq->tg;
  	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
  	u64 amount = 0, min_amount;
  
  	/* note: this is a positive sum as runtime_remaining <= 0 */
  	min_amount = sched_cfs_bandwidth_slice() - cfs_rq->runtime_remaining;
  
  	raw_spin_lock(&cfs_b->lock);
  	if (cfs_b->quota == RUNTIME_INF)
  		amount = min_amount;
  	else {
  		start_cfs_bandwidth(cfs_b);
  
  		if (cfs_b->runtime > 0) {
  			amount = min(cfs_b->runtime, min_amount);
  			cfs_b->runtime -= amount;
  			cfs_b->idle = 0;
  		}
  	}
  	raw_spin_unlock(&cfs_b->lock);
  
  	cfs_rq->runtime_remaining += amount;
  
  	return cfs_rq->runtime_remaining > 0;
  }
  
  static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec)
  {
  	/* dock delta_exec before expiring quota (as it could span periods) */
  	cfs_rq->runtime_remaining -= delta_exec;
  
  	if (likely(cfs_rq->runtime_remaining > 0))
  		return;
  
  	if (cfs_rq->throttled)
  		return;
  	/*
  	 * if we're unable to extend our runtime we resched so that the active
  	 * hierarchy can be throttled
  	 */
  	if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
  		resched_curr(rq_of(cfs_rq));
  }
  
  static __always_inline
  void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec)
  {
  	if (!cfs_bandwidth_used() || !cfs_rq->runtime_enabled)
  		return;
  
  	__account_cfs_rq_runtime(cfs_rq, delta_exec);
  }
  
  static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
  {
  	return cfs_bandwidth_used() && cfs_rq->throttled;
  }
  
  /* check whether cfs_rq, or any parent, is throttled */
  static inline int throttled_hierarchy(struct cfs_rq *cfs_rq)
  {
  	return cfs_bandwidth_used() && cfs_rq->throttle_count;
  }
  
  /*
   * Ensure that neither of the group entities corresponding to src_cpu or
   * dest_cpu are members of a throttled hierarchy when performing group
   * load-balance operations.
   */
  static inline int throttled_lb_pair(struct task_group *tg,
  				    int src_cpu, int dest_cpu)
  {
  	struct cfs_rq *src_cfs_rq, *dest_cfs_rq;
  
  	src_cfs_rq = tg->cfs_rq[src_cpu];
  	dest_cfs_rq = tg->cfs_rq[dest_cpu];
  
  	return throttled_hierarchy(src_cfs_rq) ||
  	       throttled_hierarchy(dest_cfs_rq);
  }
  
  /* updated child weight may affect parent so we have to do this bottom up */
  static int tg_unthrottle_up(struct task_group *tg, void *data)
  {
  	struct rq *rq = data;
  	struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
  
  	cfs_rq->throttle_count--;
  	if (!cfs_rq->throttle_count) {
  		/* adjust cfs_rq_clock_task() */
  		cfs_rq->throttled_clock_task_time += rq_clock_task(rq) -
  					     cfs_rq->throttled_clock_task;
  	}
  
  	return 0;
  }
  
  static int tg_throttle_down(struct task_group *tg, void *data)
  {
  	struct rq *rq = data;
  	struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
  
  	/* group is entering throttled state, stop time */
  	if (!cfs_rq->throttle_count)
  		cfs_rq->throttled_clock_task = rq_clock_task(rq);
  	cfs_rq->throttle_count++;
  
  	return 0;
  }
  
  #if defined(CONFIG_SCHED_WALT) && defined(CONFIG_SCHED_HISI_USE_WALT)
  static inline void walt_propagate_cumulative_runnable_avg(u64 *accumulated,
  							  u64 value, bool add)
  {
  	if (add)
  		*accumulated += value;
  	else
  		*accumulated -= value;
  }
  #else
  /*
   * Provide a nop definition since cumulative_runnable_avg is not
   * available in rq or cfs_rq when WALT is not enabled.
   */
  #define walt_propagate_cumulative_runnable_avg(...)
  #endif
  
  static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
  {
  	struct rq *rq = rq_of(cfs_rq);
  	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
  	struct sched_entity *se;
  	long task_delta, dequeue = 1;
  	bool empty;
  
  	se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];
  
  	/* freeze hierarchy runnable averages while throttled */
  	rcu_read_lock();
  	walk_tg_tree_from(cfs_rq->tg, tg_throttle_down, tg_nop, (void *)rq);
  	rcu_read_unlock();
  
  	task_delta = cfs_rq->h_nr_running;
  	for_each_sched_entity(se) {
  		struct cfs_rq *qcfs_rq = cfs_rq_of(se);
  		/* throttled entity or throttle-on-deactivate */
  		if (!se->on_rq)
  			break;
  
  		if (dequeue)
  			dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP);
  		qcfs_rq->h_nr_running -= task_delta;
  		walt_propagate_cumulative_runnable_avg(
  				   &qcfs_rq->cumulative_runnable_avg,
  				   cfs_rq->cumulative_runnable_avg, false);
  
  
  		if (qcfs_rq->load.weight)
  			dequeue = 0;
  	}
  
  	if (!se) {
  		sub_nr_running(rq, task_delta);
  		walt_propagate_cumulative_runnable_avg(
  				   &rq->cumulative_runnable_avg,
  				   cfs_rq->cumulative_runnable_avg, false);
  	}
  
  	cfs_rq->throttled = 1;
  	cfs_rq->throttled_clock = rq_clock(rq);
  	raw_spin_lock(&cfs_b->lock);
  	empty = list_empty(&cfs_b->throttled_cfs_rq);
  
  	/*
  	 * Add to the _head_ of the list, so that an already-started
  	 * distribute_cfs_runtime will not see us. If disribute_cfs_runtime is
  	 * not running add to the tail so that later runqueues don't get starved.
  	 */
  	if (cfs_b->distribute_running)
  		list_add_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);
  	else
  		list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);
  
  	/*
  	 * If we're the first throttled task, make sure the bandwidth
  	 * timer is running.
  	 */
  	if (empty)
  		start_cfs_bandwidth(cfs_b);
  
  	raw_spin_unlock(&cfs_b->lock);
  }
  
  void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
  {
  	struct rq *rq = rq_of(cfs_rq);
  	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
  	struct sched_entity *se;
  	int enqueue = 1;
  	long task_delta;
  	struct cfs_rq *tcfs_rq __maybe_unused = cfs_rq;
  
  	se = cfs_rq->tg->se[cpu_of(rq)];
  
  	cfs_rq->throttled = 0;
  
  	update_rq_clock(rq);
  
  	raw_spin_lock(&cfs_b->lock);
  	cfs_b->throttled_time += rq_clock(rq) - cfs_rq->throttled_clock;
  	list_del_rcu(&cfs_rq->throttled_list);
  	raw_spin_unlock(&cfs_b->lock);
  
  	/* update hierarchical throttle state */
  	walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq);
  
  	if (!cfs_rq->load.weight)
  		return;
  
  	task_delta = cfs_rq->h_nr_running;
  	for_each_sched_entity(se) {
  		if (se->on_rq)
  			enqueue = 0;
  
  		cfs_rq = cfs_rq_of(se);
  		if (enqueue)
  			enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
  		cfs_rq->h_nr_running += task_delta;
  		walt_propagate_cumulative_runnable_avg(
  				   &cfs_rq->cumulative_runnable_avg,
  				   tcfs_rq->cumulative_runnable_avg, true);
  
  		if (cfs_rq_throttled(cfs_rq))
  			break;
  	}
  
  	if (!se) {
  		add_nr_running(rq, task_delta);
  		walt_propagate_cumulative_runnable_avg(
  				   &rq->cumulative_runnable_avg,
  				   tcfs_rq->cumulative_runnable_avg, true);
  	}
  
  	/* determine whether we need to wake up potentially idle cpu */
  	if (rq->curr == rq->idle && rq->cfs.nr_running)
  		resched_curr(rq);
  }
  
  static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b, u64 remaining)
  {
  	struct cfs_rq *cfs_rq;
  	u64 runtime;
  	u64 starting_runtime = remaining;
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(cfs_rq, &cfs_b->throttled_cfs_rq,
  				throttled_list) {
  		struct rq *rq = rq_of(cfs_rq);
  		struct rq_flags rf;
  
  		rq_lock(rq, &rf);
  		if (!cfs_rq_throttled(cfs_rq))
  			goto next;
  
  		/* By the above check, this should never be true */
  		SCHED_WARN_ON(cfs_rq->runtime_remaining > 0);
  
  		runtime = -cfs_rq->runtime_remaining + 1;
  		if (runtime > remaining)
  			runtime = remaining;
  		remaining -= runtime;
  
  		cfs_rq->runtime_remaining += runtime;
  
  		/* we check whether we're throttled above */
  		if (cfs_rq->runtime_remaining > 0)
  			unthrottle_cfs_rq(cfs_rq);
  
  next:
  		rq_unlock(rq, &rf);
  
  		if (!remaining)
  			break;
  	}
  	rcu_read_unlock();
  
  	return starting_runtime - remaining;
  }
  
  /*
   * Responsible for refilling a task_group's bandwidth and unthrottling its
   * cfs_rqs as appropriate. If there has been no activity within the last
   * period the timer is deactivated until scheduling resumes; cfs_b->idle is
   * used to track this state.
   */
  static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
  {
  	u64 runtime;
  	int throttled;
  
  	/* no need to continue the timer with no bandwidth constraint */
  	if (cfs_b->quota == RUNTIME_INF)
  		goto out_deactivate;
  
  	throttled = !list_empty(&cfs_b->throttled_cfs_rq);
  	cfs_b->nr_periods += overrun;
  
  	/*
  	 * idle depends on !throttled (for the case of a large deficit), and if
  	 * we're going inactive then everything else can be deferred
  	 */
  	if (cfs_b->idle && !throttled)
  		goto out_deactivate;
  
  	__refill_cfs_bandwidth_runtime(cfs_b);
  
  	if (!throttled) {
  		/* mark as potentially idle for the upcoming period */
  		cfs_b->idle = 1;
  		return 0;
  	}
  
  	/* account preceding periods in which throttling occurred */
  	cfs_b->nr_throttled += overrun;
  
  	/*
  	 * This check is repeated as we are holding onto the new bandwidth while
  	 * we unthrottle. This can potentially race with an unthrottled group
  	 * trying to acquire new bandwidth from the global pool. This can result
  	 * in us over-using our runtime if it is all used during this loop, but
  	 * only by limited amounts in that extreme case.
  	 */
  	while (throttled && cfs_b->runtime > 0 && !cfs_b->distribute_running) {
  		runtime = cfs_b->runtime;
  		cfs_b->distribute_running = 1;
  		raw_spin_unlock(&cfs_b->lock);
  		/* we can't nest cfs_b->lock while distributing bandwidth */
  		runtime = distribute_cfs_runtime(cfs_b, runtime);
  		raw_spin_lock(&cfs_b->lock);
  
  		cfs_b->distribute_running = 0;
  		throttled = !list_empty(&cfs_b->throttled_cfs_rq);
  
  		cfs_b->runtime -= min(runtime, cfs_b->runtime);
  	}
  
  	/*
  	 * While we are ensured activity in the period following an
  	 * unthrottle, this also covers the case in which the new bandwidth is
  	 * insufficient to cover the existing bandwidth deficit.  (Forcing the
  	 * timer to remain active while there are any throttled entities.)
  	 */
  	cfs_b->idle = 0;
  
  	return 0;
  
  out_deactivate:
  	return 1;
  }
  
  /* a cfs_rq won't donate quota below this amount */
  static const u64 min_cfs_rq_runtime = 1 * NSEC_PER_MSEC;
  /* minimum remaining period time to redistribute slack quota */
  static const u64 min_bandwidth_expiration = 2 * NSEC_PER_MSEC;
  /* how long we wait to gather additional slack before distributing */
  static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC;
  
  /*
   * Are we near the end of the current quota period?
   *
   * Requires cfs_b->lock for hrtimer_expires_remaining to be safe against the
   * hrtimer base being cleared by hrtimer_start. In the case of
   * migrate_hrtimers, base is never cleared, so we are fine.
   */
  static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire)
  {
  	struct hrtimer *refresh_timer = &cfs_b->period_timer;
  	u64 remaining;
  
  	/* if the call-back is running a quota refresh is already occurring */
  	if (hrtimer_callback_running(refresh_timer))
  		return 1;
  
  	/* is a quota refresh about to occur? */
  	remaining = ktime_to_ns(hrtimer_expires_remaining(refresh_timer));
  	if (remaining < min_expire)
  		return 1;
  
  	return 0;
  }
  
  static void start_cfs_slack_bandwidth(struct cfs_bandwidth *cfs_b)
  {
  	u64 min_left = cfs_bandwidth_slack_period + min_bandwidth_expiration;
  
  	/* if there's a quota refresh soon don't bother with slack */
  	if (runtime_refresh_within(cfs_b, min_left))
  		return;
  
  	hrtimer_start(&cfs_b->slack_timer,
  			ns_to_ktime(cfs_bandwidth_slack_period),
  			HRTIMER_MODE_REL);
  }
  
  /* we know any runtime found here is valid as update_curr() precedes return */
  static void __return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
  {
  	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
  	s64 slack_runtime = cfs_rq->runtime_remaining - min_cfs_rq_runtime;
  
  	if (slack_runtime <= 0)
  		return;
  
  	raw_spin_lock(&cfs_b->lock);
  	if (cfs_b->quota != RUNTIME_INF) {
  		cfs_b->runtime += slack_runtime;
  
  		/* we are under rq->lock, defer unthrottling using a timer */
  		if (cfs_b->runtime > sched_cfs_bandwidth_slice() &&
  		    !list_empty(&cfs_b->throttled_cfs_rq))
  			start_cfs_slack_bandwidth(cfs_b);
  	}
  	raw_spin_unlock(&cfs_b->lock);
  
  	/* even if it's not valid for return we don't want to try again */
  	cfs_rq->runtime_remaining -= slack_runtime;
  }
  
  static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
  {
  	if (!cfs_bandwidth_used())
  		return;
  
  	if (!cfs_rq->runtime_enabled || cfs_rq->nr_running)
  		return;
  
  	__return_cfs_rq_runtime(cfs_rq);
  }
  
  /*
   * This is done with a timer (instead of inline with bandwidth return) since
   * it's necessary to juggle rq->locks to unthrottle their respective cfs_rqs.
   */
  static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
  {
  	u64 runtime = 0, slice = sched_cfs_bandwidth_slice();
  
  	/* confirm we're still not at a refresh boundary */
  	raw_spin_lock(&cfs_b->lock);
  	if (cfs_b->distribute_running) {
  		raw_spin_unlock(&cfs_b->lock);
  		return;
  	}
  
  	if (runtime_refresh_within(cfs_b, min_bandwidth_expiration)) {
  		raw_spin_unlock(&cfs_b->lock);
  		return;
  	}
  
  	if (cfs_b->quota != RUNTIME_INF && cfs_b->runtime > slice)
  		runtime = cfs_b->runtime;
  
  	if (runtime)
  		cfs_b->distribute_running = 1;
  
  	raw_spin_unlock(&cfs_b->lock);
  
  	if (!runtime)
  		return;
  
  	runtime = distribute_cfs_runtime(cfs_b, runtime);
  
  	raw_spin_lock(&cfs_b->lock);
  	cfs_b->runtime -= min(runtime, cfs_b->runtime);
  	cfs_b->distribute_running = 0;
  	raw_spin_unlock(&cfs_b->lock);
  }
  
  /*
   * When a group wakes up we want to make sure that its quota is not already
   * expired/exceeded, otherwise it may be allowed to steal additional ticks of
   * runtime as update_curr() throttling can not not trigger until it's on-rq.
   */
  static void check_enqueue_throttle(struct cfs_rq *cfs_rq)
  {
  	if (!cfs_bandwidth_used())
  		return;
  
  	/* an active group must be handled by the update_curr()->put() path */
  	if (!cfs_rq->runtime_enabled || cfs_rq->curr)
  		return;
  
  	/* ensure the group is not already throttled */
  	if (cfs_rq_throttled(cfs_rq))
  		return;
  
  	/* update runtime allocation */
  	account_cfs_rq_runtime(cfs_rq, 0);
  	if (cfs_rq->runtime_remaining <= 0)
  		throttle_cfs_rq(cfs_rq);
  }
  
  static void sync_throttle(struct task_group *tg, int cpu)
  {
  	struct cfs_rq *pcfs_rq, *cfs_rq;
  
  	if (!cfs_bandwidth_used())
  		return;
  
  	if (!tg->parent)
  		return;
  
  	cfs_rq = tg->cfs_rq[cpu];
  	pcfs_rq = tg->parent->cfs_rq[cpu];
  
  	cfs_rq->throttle_count = pcfs_rq->throttle_count;
  	cfs_rq->throttled_clock_task = rq_clock_task(cpu_rq(cpu));
  }
  
  /* conditionally throttle active cfs_rq's from put_prev_entity() */
  static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
  {
  	if (!cfs_bandwidth_used())
  		return false;
  
  	if (likely(!cfs_rq->runtime_enabled || cfs_rq->runtime_remaining > 0))
  		return false;
  
  	/*
  	 * it's possible for a throttled entity to be forced into a running
  	 * state (e.g. set_curr_task), in this case we're finished.
  	 */
  	if (cfs_rq_throttled(cfs_rq))
  		return true;
  
  	throttle_cfs_rq(cfs_rq);
  	return true;
  }
  
  static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer)
  {
  	struct cfs_bandwidth *cfs_b =
  		container_of(timer, struct cfs_bandwidth, slack_timer);
  
  	do_sched_cfs_slack_timer(cfs_b);
  
  	return HRTIMER_NORESTART;
  }
  
  extern const u64 max_cfs_quota_period;
  
  static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
  {
  	struct cfs_bandwidth *cfs_b =
  		container_of(timer, struct cfs_bandwidth, period_timer);
  	int overrun;
  	int idle = 0;
  	int count = 0;
  
  	raw_spin_lock(&cfs_b->lock);
  	for (;;) {
  		overrun = hrtimer_forward_now(timer, cfs_b->period);
  		if (!overrun)
  			break;
  
  		if (++count > 3) {
  			u64 new, old = ktime_to_ns(cfs_b->period);
  
  			new = (old * 147) / 128; /* ~115% */
  			new = min(new, max_cfs_quota_period);
  
  			cfs_b->period = ns_to_ktime(new);
  
  			/* since max is 1s, this is limited to 1e9^2, which fits in u64 */
  			cfs_b->quota *= new;
  			cfs_b->quota = div64_u64(cfs_b->quota, old);
  
  			pr_warn_ratelimited(
  				"cfs_period_timer[cpu%d]: period too short, scaling up (new cfs_period_us %lld, cfs_quota_us = %lld)\n",
  				smp_processor_id(),
  				div_u64(new, NSEC_PER_USEC),
  				div_u64(cfs_b->quota, NSEC_PER_USEC));
  
  			/* reset count so we don't come right back in here */
  			count = 0;
  		}
  
  		idle = do_sched_cfs_period_timer(cfs_b, overrun);
  	}
  	if (idle)
  		cfs_b->period_active = 0;
  	raw_spin_unlock(&cfs_b->lock);
  
  	return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
  }
  
  void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
  {
  	raw_spin_lock_init(&cfs_b->lock);
  	cfs_b->runtime = 0;
  	cfs_b->quota = RUNTIME_INF;
  	cfs_b->period = ns_to_ktime(default_cfs_period());
  
  	INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq);
  	hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
  	cfs_b->period_timer.function = sched_cfs_period_timer;
  	hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
  	cfs_b->slack_timer.function = sched_cfs_slack_timer;
  	cfs_b->distribute_running = 0;
  }
  
  static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq)
  {
  	cfs_rq->runtime_enabled = 0;
  	INIT_LIST_HEAD(&cfs_rq->throttled_list);
  }
  
  void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
  {
  	lockdep_assert_held(&cfs_b->lock);
  
  	if (!cfs_b->period_active) {
  		cfs_b->period_active = 1;
  		hrtimer_forward_now(&cfs_b->period_timer, cfs_b->period);
  		hrtimer_start_expires(&cfs_b->period_timer, HRTIMER_MODE_ABS_PINNED);
  	}
  }
  
  static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
  {
  	/* init_cfs_bandwidth() was not called */
  	if (!cfs_b->throttled_cfs_rq.next)
  		return;
  
  	hrtimer_cancel(&cfs_b->period_timer);
  	hrtimer_cancel(&cfs_b->slack_timer);
  }
  
  /*
   * Both these cpu hotplug callbacks race against unregister_fair_sched_group()
   *
   * The race is harmless, since modifying bandwidth settings of unhooked group
   * bits doesn't do much.
   */
  
  /* cpu online calback */
  static void __maybe_unused update_runtime_enabled(struct rq *rq)
  {
  	struct task_group *tg;
  
  	lockdep_assert_held(&rq->lock);
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(tg, &task_groups, list) {
  		struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
  		struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
  
  		raw_spin_lock(&cfs_b->lock);
  		cfs_rq->runtime_enabled = cfs_b->quota != RUNTIME_INF;
  		raw_spin_unlock(&cfs_b->lock);
  	}
  	rcu_read_unlock();
  }
  
  /* cpu offline callback */
  static void __maybe_unused unthrottle_offline_cfs_rqs(struct rq *rq)
  {
  	struct task_group *tg;
  
  	lockdep_assert_held(&rq->lock);
  
  	rcu_read_lock();
  	list_for_each_entry_rcu(tg, &task_groups, list) {
  		struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
  
  		if (!cfs_rq->runtime_enabled)
  			continue;
  
  		/*
  		 * clock_task is not advancing so we just need to make sure
  		 * there's some valid quota amount
  		 */
  		cfs_rq->runtime_remaining = 1;
  		/*
  		 * Offline rq is schedulable till cpu is completely disabled
  		 * in take_cpu_down(), so we prevent new cfs throttling here.
  		 */
  		cfs_rq->runtime_enabled = 0;
  
  		if (cfs_rq_throttled(cfs_rq))
  			unthrottle_cfs_rq(cfs_rq);
  	}
  	rcu_read_unlock();
  }
  
  #ifdef CONFIG_SCHED_WALT
  static void walt_fixup_cumulative_runnable_avg_fair(struct rq *rq,
  						    struct task_struct *p,
  						    u64 new_task_load)
  {
  #ifdef CONFIG_SCHED_HISI_USE_WALT
  	struct cfs_rq *cfs_rq;
  	struct sched_entity *se = &p->se;
  	s64 task_load_delta = (s64)new_task_load - p->ravg.demand;
  
  	for_each_sched_entity(se) {
  		cfs_rq = cfs_rq_of(se);
  
  		cfs_rq->cumulative_runnable_avg += task_load_delta;
  		if (cfs_rq_throttled(cfs_rq))
  			break;
  	}
  
  	/* Fix up rq only if we didn't find any throttled cfs_rq */
  	if (!se)
  		walt_fixup_cumulative_runnable_avg(rq, p, new_task_load);
  #endif
  }
  
  #endif /* CONFIG_SCHED_WALT */
  
  #else /* CONFIG_CFS_BANDWIDTH */
  static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq)
  {
  	return rq_clock_task(rq_of(cfs_rq));
  }
  
  static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec) {}
  static bool check_cfs_rq_runtime(struct cfs_rq *cfs_rq) { return false; }
  static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {}
  static inline void sync_throttle(struct task_group *tg, int cpu) {}
  static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
  
  static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
  {
  	return 0;
  }
  
  static inline int throttled_hierarchy(struct cfs_rq *cfs_rq)
  {
  	return 0;
  }
  
  static inline int throttled_lb_pair(struct task_group *tg,
  				    int src_cpu, int dest_cpu)
  {
  	return 0;
  }
  
  void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
  #endif
  
  static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
  {
  	return NULL;
  }
  static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
  static inline void update_runtime_enabled(struct rq *rq) {}
  static inline void unthrottle_offline_cfs_rqs(struct rq *rq) {}
  
  #define walt_fixup_cumulative_runnable_avg_fair \
  	walt_fixup_cumulative_runnable_avg
  
  #endif /* CONFIG_CFS_BANDWIDTH */
  
  /**************************************************
   * CFS operations on tasks:
   */
  
  #ifdef CONFIG_SCHED_HRTICK
  static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
  {
  	struct sched_entity *se = &p->se;
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  
  	SCHED_WARN_ON(task_rq(p) != rq);
  
  	if (rq->cfs.h_nr_running > 1) {
  		u64 slice = sched_slice(cfs_rq, se);
  		u64 ran = se->sum_exec_runtime - se->prev_sum_exec_runtime;
  		s64 delta = slice - ran;
  
  		if (delta < 0) {
  			if (rq->curr == p)
  				resched_curr(rq);
  			return;
  		}
  		hrtick_start(rq, delta);
  	}
  }
  
  /*
   * called from enqueue/dequeue and updates the hrtick when the
   * current task is from our class and nr_running is low enough
   * to matter.
   */
  static void hrtick_update(struct rq *rq)
  {
  	struct task_struct *curr = rq->curr;
  
  	if (!hrtick_enabled(rq) || curr->sched_class != &fair_sched_class)
  		return;
  
  	if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency)
  		hrtick_start_fair(rq, curr);
  }
  #else /* !CONFIG_SCHED_HRTICK */
  static inline void
  hrtick_start_fair(struct rq *rq, struct task_struct *p)
  {
  }
  
  static inline void hrtick_update(struct rq *rq)
  {
  }
  #endif
  
  #ifdef CONFIG_SMP
  static bool cpu_overutilized(int cpu);
  
  static bool sd_overutilized(struct sched_domain *sd)
  {
  	return sd->shared->overutilized;
  }
  
  static void set_sd_overutilized(struct sched_domain *sd)
  {
  	trace_sched_overutilized(sd, sd->shared->overutilized, true);
  	sd->shared->overutilized = true;
  }
  
  static void clear_sd_overutilized(struct sched_domain *sd)
  {
  	trace_sched_overutilized(sd, sd->shared->overutilized, false);
  	sd->shared->overutilized = false;
  }
  
  static inline void update_overutilized_status(struct rq *rq)
  {
  	struct sched_domain *sd;
  
  	rcu_read_lock();
  	sd = rcu_dereference(rq->sd);
  	if (sd && !sd_overutilized(sd) &&
  	    cpu_overutilized(rq->cpu))
  		set_sd_overutilized(sd);
  	rcu_read_unlock();
  }
  
  unsigned long boosted_cpu_util(int cpu);
  #else
  
  #define update_overutilized_status(rq) do {} while (0)
  #define boosted_cpu_util(cpu) cpu_util_freq(cpu)
  
  #endif /* CONFIG_SMP */
  
  #ifdef CONFIG_SCHED_HISI_VIP
  #define VIP_TASK_LIMIT_RUNNING_NS 50000000 /* 50ms */
  #define VIP_TASK_LIMIT_ITER_NUM   20 /* max 20 for an rq */
  
  static void enqueue_hisi_vip_thread(struct rq *rq, struct task_struct *p)
  {
  	if (!p->hisi_vip_prio)
  		return;
  
  	if (unlikely(!list_empty(&p->hisi_vip_entry))) {
  		pr_warn("task %d not dequeued as vip\n", p->pid);
  		return;
  	}
  
  	p->hisi_vip_last_queued = rq_clock(rq);
  	list_add(&p->hisi_vip_entry, &rq->hisi_vip_thread_list);
  
  	if (p->hisi_vip_prio > rq->highest_hisi_vip_prio)
  		rq->highest_hisi_vip_prio = p->hisi_vip_prio;
  }
  
  static void dequeue_hisi_vip_thread(struct rq *rq, struct task_struct *p)
  {
  	struct task_struct *task = NULL;
  	unsigned int highest_prio, task_cnt;
  
  	if (!p->hisi_vip_prio)
  		return;
  
  	if (unlikely(list_empty(&p->hisi_vip_entry))) {
  		pr_warn("task %d not enqueued as vip\n", p->pid);
  		return;
  	}
  
  	p->hisi_vip_last_queued = 0;
  	list_del_init(&p->hisi_vip_entry);
  
  	highest_prio = 0;
  	task_cnt = 0;
  	list_for_each_entry(task, &rq->hisi_vip_thread_list, hisi_vip_entry) {
  		highest_prio = max(highest_prio, task->hisi_vip_prio);
  
  		if (++task_cnt >= VIP_TASK_LIMIT_ITER_NUM)
  			break;
  	}
  
  	rq->highest_hisi_vip_prio = highest_prio;
  }
  
  static struct task_struct *
  pick_next_hisi_vip_thread(struct rq *rq)
  {
  	struct task_struct *task = NULL, *leftmost_task = NULL, *n = NULL;
  	unsigned int task_cnt = 0;
  
  	list_for_each_entry_safe(task, n, &rq->hisi_vip_thread_list, hisi_vip_entry) {
  		if (unlikely(task_rq(task) != rq)) {
  			pr_warn("task %d on another rq\n", task->pid);
  			list_del_init(&task->hisi_vip_entry);
  			continue;
  		}
  
  		if (unlikely(!task_on_rq_queued(task))) {
  			pr_warn("task %d not queued\n", task->pid);
  			list_del_init(&task->hisi_vip_entry);
  			continue;
  		}
  
  		if (!leftmost_task ||
  		    task->hisi_vip_prio > leftmost_task->hisi_vip_prio ||
  		    (task->hisi_vip_prio == leftmost_task->hisi_vip_prio &&
  		     entity_before(&task->se, &leftmost_task->se)))
  			leftmost_task = task;
  
  		if (++task_cnt >= VIP_TASK_LIMIT_ITER_NUM)
  			break;
  	}
  
  	if (leftmost_task) {
  		s64 enqueue_time;
  
  		trace_sched_pick_next_hisi_vip(leftmost_task);
  
  		/*
  		 * Waking someone with WF_SYNC.
  		 * Let the wakee have a chance to preempt and run.
  		 */
  		if (test_tsk_thread_flag(leftmost_task, TIF_WAKE_SYNC))
  			return NULL;
  
  		/*
  		 * Skip picking the vip task if it has been enqueued too long
  		 * to prevent starving or even livelock.
  		 */
  		enqueue_time = rq_clock(rq) -
  				leftmost_task->hisi_vip_last_queued;
  		if (unlikely(enqueue_time > VIP_TASK_LIMIT_RUNNING_NS))
  			return NULL;
  	}
  
  	return leftmost_task;
  }
  
  int set_hisi_vip_prio(struct task_struct *p, unsigned int prio)
  {
  	struct rq_flags rf;
  	struct rq *rq;
  	int retval = -EINVAL;
  
  	rq = task_rq_lock(p, &rf);
  
  	if (p->sched_class == &fair_sched_class) {
  		bool queued = task_on_rq_queued(p);
  
  		if (queued) {
  			update_rq_clock(rq);
  			dequeue_hisi_vip_thread(rq, p);
  		}
  
  		p->hisi_vip_prio = prio;
  
  		if (queued)
  			enqueue_hisi_vip_thread(rq, p);
  
  		retval = 0;
  	}
  
  	task_rq_unlock(rq, p, &rf);
  	return retval;
  }
  #endif /* CONFIG_SCHED_HISI_VIP */
  
  /*
   * The enqueue_task method is called before nr_running is
   * increased. Here we update the fair scheduling stats and
   * then put the task into the rbtree:
   */
  static void
  enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
  {
  	struct cfs_rq *cfs_rq;
  	struct sched_entity *se = &p->se;
  	int task_new = !(flags & ENQUEUE_WAKEUP);
  
  	/*
  	 * The code below (indirectly) updates schedutil which looks at
  	 * the cfs_rq utilization to select a frequency.
  	 * Let's add the task's estimated utilization to the cfs_rq's
  	 * estimated utilization, before we update schedutil.
  	 */
  	util_est_enqueue(&rq->cfs, p);
  
  	/*
  	 * The code below (indirectly) updates schedutil which looks at
  	 * the cfs_rq utilization to select a frequency.
  	 * Let's update schedtune here to ensure the boost value of the
  	 * current task is accounted for in the selection of the OPP.
  	 *
  	 * We do it also in the case where we enqueue a throttled task;
  	 * we could argue that a throttled task should not boost a CPU,
  	 * however:
  	 * a) properly implementing CPU boosting considering throttled
  	 *    tasks will increase a lot the complexity of the solution
  	 * b) it's not easy to quantify the benefits introduced by
  	 *    such a more complex solution.
  	 * Thus, for the time being we go for the simple solution and boost
  	 * also for throttled RQs.
  	 */
  	schedtune_enqueue_task(p, cpu_of(rq));
  
  	/*
  	 * If in_iowait is set, the code below may not trigger any cpufreq
  	 * utilization updates, so do it here explicitly with the IOWAIT flag
  	 * passed.
  	 */
  	if (p->in_iowait)
  		cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT);
  
  	for_each_sched_entity(se) {
  		if (se->on_rq)
  			break;
  		cfs_rq = cfs_rq_of(se);
  		enqueue_entity(cfs_rq, se, flags);
  
  		/*
  		 * end evaluation on encountering a throttled cfs_rq
  		 *
  		 * note: in the case of encountering a throttled cfs_rq we will
  		 * post the final h_nr_running increment below.
  		 */
  		if (cfs_rq_throttled(cfs_rq))
  			break;
  		cfs_rq->h_nr_running++;
  		walt_inc_cfs_cumulative_runnable_avg(cfs_rq, p);
  
  		flags = ENQUEUE_WAKEUP;
  	}
  
  #ifdef CONFIG_HW_VIP_THREAD
  	enqueue_vip_thread(rq, p);
  #endif
  #ifdef CONFIG_SCHED_HISI_VIP
  	enqueue_hisi_vip_thread(rq, p);
  #endif
  
  	for_each_sched_entity(se) {
  		cfs_rq = cfs_rq_of(se);
  		cfs_rq->h_nr_running++;
  		walt_inc_cfs_cumulative_runnable_avg(cfs_rq, p);
  
  		if (cfs_rq_throttled(cfs_rq))
  			break;
  
  		update_load_avg(se, UPDATE_TG);
  		update_cfs_shares(se);
  	}
  
  	if (!se) {
  		add_nr_running(rq, 1);
  		if (!task_new)
  			update_overutilized_status(rq);
  #ifdef CONFIG_HISI_CORE_CTRL
  		inc_cfs_nr_heavy_running(rq, p);
  #endif
  		walt_inc_cumulative_runnable_avg(rq, p);
  	}
  
  	hrtick_update(rq);
  }
  
  static void set_next_buddy(struct sched_entity *se);
  
  /*
   * The dequeue_task method is called before nr_running is
   * decreased. We remove the task from the rbtree and
   * update the fair scheduling stats:
   */
  static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
  {
  	struct cfs_rq *cfs_rq;
  	struct sched_entity *se = &p->se;
  	int task_sleep = flags & DEQUEUE_SLEEP;
  
  	/*
  	 * The code below (indirectly) updates schedutil which looks at
  	 * the cfs_rq utilization to select a frequency.
  	 * Let's update schedtune here to ensure the boost value of the
  	 * current task is not more accounted for in the selection of the OPP.
  	 */
  	schedtune_dequeue_task(p, cpu_of(rq));
  
  	for_each_sched_entity(se) {
  		cfs_rq = cfs_rq_of(se);
  		dequeue_entity(cfs_rq, se, flags);
  
  		/*
  		 * end evaluation on encountering a throttled cfs_rq
  		 *
  		 * note: in the case of encountering a throttled cfs_rq we will
  		 * post the final h_nr_running decrement below.
  		*/
  		if (cfs_rq_throttled(cfs_rq))
  			break;
  		cfs_rq->h_nr_running--;
  		walt_dec_cfs_cumulative_runnable_avg(cfs_rq, p);
  
  		/* Don't dequeue parent if it has other entities besides us */
  		if (cfs_rq->load.weight) {
  			/* Avoid re-evaluating load for this entity: */
  			se = parent_entity(se);
  			/*
  			 * Bias pick_next to pick a task from this cfs_rq, as
  			 * p is sleeping when it is within its sched_slice.
  			 */
  			if (task_sleep && se && !throttled_hierarchy(cfs_rq))
  				set_next_buddy(se);
  			break;
  		}
  		flags |= DEQUEUE_SLEEP;
  	}
  
  #ifdef CONFIG_HW_VIP_THREAD
  	dequeue_vip_thread(rq, p);
  #endif
  #ifdef CONFIG_SCHED_HISI_VIP
  	dequeue_hisi_vip_thread(rq, p);
  #endif
  
  	for_each_sched_entity(se) {
  		cfs_rq = cfs_rq_of(se);
  		cfs_rq->h_nr_running--;
  		walt_dec_cfs_cumulative_runnable_avg(cfs_rq, p);
  
  		if (cfs_rq_throttled(cfs_rq))
  			break;
  
  		update_load_avg(se, UPDATE_TG);
  		update_cfs_shares(se);
  	}
  
  	if (!se) {
  		sub_nr_running(rq, 1);
  		walt_dec_cumulative_runnable_avg(rq, p);
  #ifdef CONFIG_HISI_CORE_CTRL
  		dec_cfs_nr_heavy_running(rq, p);
  #endif
  	}
  
  	util_est_dequeue(&rq->cfs, p, task_sleep);
  	hrtick_update(rq);
  }
  
  #ifdef CONFIG_SMP
  
  /* Working cpumask for: load_balance, load_balance_newidle. */
  DEFINE_PER_CPU(cpumask_var_t, load_balance_mask);
  DEFINE_PER_CPU(cpumask_var_t, select_idle_mask);
  
  #ifdef CONFIG_NO_HZ_COMMON
  /*
   * per rq 'load' arrray crap; XXX kill this.
   */
  
  /*
   * The exact cpuload calculated at every tick would be:
   *
   *   load' = (1 - 1/2^i) * load + (1/2^i) * cur_load
   *
   * If a cpu misses updates for n ticks (as it was idle) and update gets
   * called on the n+1-th tick when cpu may be busy, then we have:
   *
   *   load_n   = (1 - 1/2^i)^n * load_0
   *   load_n+1 = (1 - 1/2^i)   * load_n + (1/2^i) * cur_load
   *
   * decay_load_missed() below does efficient calculation of
   *
   *   load' = (1 - 1/2^i)^n * load
   *
   * Because x^(n+m) := x^n * x^m we can decompose any x^n in power-of-2 factors.
   * This allows us to precompute the above in said factors, thereby allowing the
   * reduction of an arbitrary n in O(log_2 n) steps. (See also
   * fixed_power_int())
   *
   * The calculation is approximated on a 128 point scale.
   */
  #define DEGRADE_SHIFT		7
  
  static const u8 degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128};
  static const u8 degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = {
  	{   0,   0,  0,  0,  0,  0, 0, 0 },
  	{  64,  32,  8,  0,  0,  0, 0, 0 },
  	{  96,  72, 40, 12,  1,  0, 0, 0 },
  	{ 112,  98, 75, 43, 15,  1, 0, 0 },
  	{ 120, 112, 98, 76, 45, 16, 2, 0 }
  };
  
  /*
   * Update cpu_load for any missed ticks, due to tickless idle. The backlog
   * would be when CPU is idle and so we just decay the old load without
   * adding any new load.
   */
  static unsigned long
  decay_load_missed(unsigned long load, unsigned long missed_updates, int idx)
  {
  	int j = 0;
  
  	if (!missed_updates)
  		return load;
  
  	if (missed_updates >= degrade_zero_ticks[idx])
  		return 0;
  
  	if (idx == 1)
  		return load >> missed_updates;
  
  	while (missed_updates) {
  		if (missed_updates % 2)
  			load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT;
  
  		missed_updates >>= 1;
  		j++;
  	}
  	return load;
  }
  #endif /* CONFIG_NO_HZ_COMMON */
  
  /**
   * __cpu_load_update - update the rq->cpu_load[] statistics
   * @this_rq: The rq to update statistics for
   * @this_load: The current load
   * @pending_updates: The number of missed updates
   *
   * Update rq->cpu_load[] statistics. This function is usually called every
   * scheduler tick (TICK_NSEC).
   *
   * This function computes a decaying average:
   *
   *   load[i]' = (1 - 1/2^i) * load[i] + (1/2^i) * load
   *
   * Because of NOHZ it might not get called on every tick which gives need for
   * the @pending_updates argument.
   *
   *   load[i]_n = (1 - 1/2^i) * load[i]_n-1 + (1/2^i) * load_n-1
   *             = A * load[i]_n-1 + B ; A := (1 - 1/2^i), B := (1/2^i) * load
   *             = A * (A * load[i]_n-2 + B) + B
   *             = A * (A * (A * load[i]_n-3 + B) + B) + B
   *             = A^3 * load[i]_n-3 + (A^2 + A + 1) * B
   *             = A^n * load[i]_0 + (A^(n-1) + A^(n-2) + ... + 1) * B
   *             = A^n * load[i]_0 + ((1 - A^n) / (1 - A)) * B
   *             = (1 - 1/2^i)^n * (load[i]_0 - load) + load
   *
   * In the above we've assumed load_n := load, which is true for NOHZ_FULL as
   * any change in load would have resulted in the tick being turned back on.
   *
   * For regular NOHZ, this reduces to:
   *
   *   load[i]_n = (1 - 1/2^i)^n * load[i]_0
   *
   * see decay_load_misses(). For NOHZ_FULL we get to subtract and add the extra
   * term.
   */
  static void cpu_load_update(struct rq *this_rq, unsigned long this_load,
  			    unsigned long pending_updates)
  {
  	unsigned long __maybe_unused tickless_load = this_rq->cpu_load[0];
  	int i, scale;
  
  	this_rq->nr_load_updates++;
  
  	/* Update our load: */
  	this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */
  	for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) {
  		unsigned long old_load, new_load;
  
  		/* scale is effectively 1 << i now, and >> i divides by scale */
  
  		old_load = this_rq->cpu_load[i];
  #ifdef CONFIG_NO_HZ_COMMON
  		old_load = decay_load_missed(old_load, pending_updates - 1, i);
  		if (tickless_load) {
  			old_load -= decay_load_missed(tickless_load, pending_updates - 1, i);
  			/*
  			 * old_load can never be a negative value because a
  			 * decayed tickless_load cannot be greater than the
  			 * original tickless_load.
  			 */
  			old_load += tickless_load;
  		}
  #endif
  		new_load = this_load;
  		/*
  		 * Round up the averaging division if load is increasing. This
  		 * prevents us from getting stuck on 9 if the load is 10, for
  		 * example.
  		 */
  		if (new_load > old_load)
  			new_load += scale - 1;
  
  		this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i;
  	}
  
  	sched_avg_update(this_rq);
  }
  
  /* Used instead of source_load when we know the type == 0 */
  static unsigned long weighted_cpuload(struct rq *rq)
  {
  	return cfs_rq_runnable_load_avg(&rq->cfs);
  }
  
  #ifdef CONFIG_NO_HZ_COMMON
  /*
   * There is no sane way to deal with nohz on smp when using jiffies because the
   * cpu doing the jiffies update might drift wrt the cpu doing the jiffy reading
   * causing off-by-one errors in observed deltas; {0,2} instead of {1,1}.
   *
   * Therefore we need to avoid the delta approach from the regular tick when
   * possible since that would seriously skew the load calculation. This is why we
   * use cpu_load_update_periodic() for CPUs out of nohz. However we'll rely on
   * jiffies deltas for updates happening while in nohz mode (idle ticks, idle
   * loop exit, nohz_idle_balance, nohz full exit...)
   *
   * This means we might still be one tick off for nohz periods.
   */
  
  static void cpu_load_update_nohz(struct rq *this_rq,
  				 unsigned long curr_jiffies,
  				 unsigned long load)
  {
  	unsigned long pending_updates;
  
  	pending_updates = curr_jiffies - this_rq->last_load_update_tick;
  	if (pending_updates) {
  		this_rq->last_load_update_tick = curr_jiffies;
  		/*
  		 * In the regular NOHZ case, we were idle, this means load 0.
  		 * In the NOHZ_FULL case, we were non-idle, we should consider
  		 * its weighted load.
  		 */
  		cpu_load_update(this_rq, load, pending_updates);
  	}
  }
  
  /*
   * Called from nohz_idle_balance() to update the load ratings before doing the
   * idle balance.
   */
  static void cpu_load_update_idle(struct rq *this_rq)
  {
  	/*
  	 * bail if there's load or we're actually up-to-date.
  	 */
  	if (weighted_cpuload(this_rq))
  		return;
  
  	cpu_load_update_nohz(this_rq, READ_ONCE(jiffies), 0);
  }
  
  /*
   * Record CPU load on nohz entry so we know the tickless load to account
   * on nohz exit. cpu_load[0] happens then to be updated more frequently
   * than other cpu_load[idx] but it should be fine as cpu_load readers
   * shouldn't rely into synchronized cpu_load[*] updates.
   */
  void cpu_load_update_nohz_start(void)
  {
  	struct rq *this_rq = this_rq();
  
  	/*
  	 * This is all lockless but should be fine. If weighted_cpuload changes
  	 * concurrently we'll exit nohz. And cpu_load write can race with
  	 * cpu_load_update_idle() but both updater would be writing the same.
  	 */
  	this_rq->cpu_load[0] = weighted_cpuload(this_rq);
  }
  
  /*
   * Account the tickless load in the end of a nohz frame.
   */
  void cpu_load_update_nohz_stop(void)
  {
  	unsigned long curr_jiffies = READ_ONCE(jiffies);
  	struct rq *this_rq = this_rq();
  	unsigned long load;
  	struct rq_flags rf;
  
  	if (curr_jiffies == this_rq->last_load_update_tick)
  		return;
  
  	load = weighted_cpuload(this_rq);
  	rq_lock(this_rq, &rf);
  	update_rq_clock(this_rq);
  	cpu_load_update_nohz(this_rq, curr_jiffies, load);
  	rq_unlock(this_rq, &rf);
  }
  #else /* !CONFIG_NO_HZ_COMMON */
  static inline void cpu_load_update_nohz(struct rq *this_rq,
  					unsigned long curr_jiffies,
  					unsigned long load) { }
  #endif /* CONFIG_NO_HZ_COMMON */
  
  static void cpu_load_update_periodic(struct rq *this_rq, unsigned long load)
  {
  #ifdef CONFIG_NO_HZ_COMMON
  	/* See the mess around cpu_load_update_nohz(). */
  	this_rq->last_load_update_tick = READ_ONCE(jiffies);
  #endif
  	cpu_load_update(this_rq, load, 1);
  }
  
  /*
   * Called from scheduler_tick()
   */
  void cpu_load_update_active(struct rq *this_rq)
  {
  	unsigned long load = weighted_cpuload(this_rq);
  
  	if (tick_nohz_tick_stopped())
  		cpu_load_update_nohz(this_rq, READ_ONCE(jiffies), load);
  	else
  		cpu_load_update_periodic(this_rq, load);
  }
  
  /*
   * Return a low guess at the load of a migration-source cpu weighted
   * according to the scheduling class and "nice" value.
   *
   * We want to under-estimate the load of migration sources, to
   * balance conservatively.
   */
  static unsigned long source_load(int cpu, int type)
  {
  	struct rq *rq = cpu_rq(cpu);
  	unsigned long total = weighted_cpuload(rq);
  
  	if (type == 0 || !sched_feat(LB_BIAS))
  		return total;
  
  	return min(rq->cpu_load[type-1], total);
  }
  
  /*
   * Return a high guess at the load of a migration-target cpu weighted
   * according to the scheduling class and "nice" value.
   */
  static unsigned long target_load(int cpu, int type)
  {
  	struct rq *rq = cpu_rq(cpu);
  	unsigned long total = weighted_cpuload(rq);
  
  	if (type == 0 || !sched_feat(LB_BIAS))
  		return total;
  
  	return max(rq->cpu_load[type-1], total);
  }
  
  static unsigned long cpu_avg_load_per_task(int cpu)
  {
  	struct rq *rq = cpu_rq(cpu);
  	unsigned long nr_running = READ_ONCE(rq->cfs.h_nr_running);
  	unsigned long load_avg = weighted_cpuload(rq);
  
  	if (nr_running)
  		return load_avg / nr_running;
  
  	return 0;
  }
  
  static void record_wakee(struct task_struct *p)
  {
  	/*
  	 * Only decay a single time; tasks that have less then 1 wakeup per
  	 * jiffy will not have built up many flips.
  	 */
  	if (time_after(jiffies, current->wakee_flip_decay_ts + HZ)) {
  		current->wakee_flips >>= 1;
  		current->wakee_flip_decay_ts = jiffies;
  	}
  
  	if (current->last_wakee != p) {
  		current->last_wakee = p;
  		current->wakee_flips++;
  	}
  }
  
  /*
   * Returns the current capacity of cpu after applying both
   * cpu and freq scaling.
   */
  unsigned long capacity_curr_of(int cpu)
  {
  	unsigned long max_cap = cpu_rq(cpu)->cpu_capacity_orig;
  	unsigned long scale_freq = arch_scale_freq_capacity(NULL, cpu);
  
  	return cap_scale(max_cap, scale_freq);
  }
  
  unsigned long capacity_min_of(int cpu)
  {
  	if (!sched_feat(MIN_CAPACITY_CAPPING))
  		return 0;
  	return arch_scale_cpu_capacity(NULL, cpu) *
  		  arch_scale_min_freq_capacity(NULL, cpu)
  		  >> SCHED_CAPACITY_SHIFT;
  }
  
  inline bool energy_aware(void)
  {
  	return sched_feat(ENERGY_AWARE);
  }
  
  /*
   * __cpu_norm_util() returns the cpu util relative to a specific capacity,
   * i.e. it's busy ratio, in the range [0..SCHED_CAPACITY_SCALE] which is useful
   * for energy calculations. Using the scale-invariant util returned by
   * cpu_util() and approximating scale-invariant util by:
   *
   *   util ~ (curr_freq/max_freq)*1024 * capacity_orig/1024 * running_time/time
   *
   * the normalized util can be found using the specific capacity.
   *
   *   capacity = capacity_orig * curr_freq/max_freq
   *
   *   norm_util = running_time/time ~ util/capacity
   */
  static unsigned long __cpu_norm_util(unsigned long util, unsigned long capacity)
  {
  	if (util >= capacity)
  		return SCHED_CAPACITY_SCALE;
  
  	return (util << SCHED_CAPACITY_SHIFT)/capacity;
  }
  
  /*
   * CPU candidates.
   *
   * These are labels to reference CPU candidates for an energy_diff.
   * Currently we support only two possible candidates: the task's previous CPU
   * and another candiate CPU.
   * More advanced/aggressive EAS selection policies can consider more
   * candidates.
   */
  #define EAS_CPU_PRV	0
  #define EAS_CPU_NXT	1
  #define EAS_CPU_BKP	2
  
  /*
   * energy_diff - supports the computation of the estimated energy impact in
   * moving a "task"'s "util_delta" between different CPU candidates.
   */
  /*
   * NOTE: When using or examining WALT task signals, all wakeup
   * latency is included as busy time for task util.
   *
   * This is relevant here because:
   * When debugging is enabled, it can take as much as 1ms to
   * write the output to the trace buffer for each eenv
   * scenario. For periodic tasks where the sleep time is of
   * a similar order, the WALT task util can be inflated.
   *
   * Further, and even without debugging enabled,
   * task wakeup latency changes depending upon the EAS
   * wakeup algorithm selected - FIND_BEST_TARGET only does
   * energy calculations for up to 2 candidate CPUs. When
   * NO_FIND_BEST_TARGET is configured, we can potentially
   * do an energy calculation across all CPUS in the system.
   *
   * The impact to WALT task util on a Juno board
   * running a periodic task which only sleeps for 200usec
   * between 1ms activations has been measured.
   * (i.e. the wakeup latency induced by energy calculation
   * and debug output is double the desired sleep time and
   * almost equivalent to the runtime which is more-or-less
   * the worst case possible for this test)
   *
   * In this scenario, a task which has a PELT util of around
   * 220 is inflated under WALT to have util around 400.
   *
   * This is simply a property of the way WALT includes
   * wakeup latency in busy time while PELT does not.
   *
   * Hence - be careful when enabling DEBUG_EENV_DECISIONS
   * expecially if WALT is the task signal.
   */
  /*#define DEBUG_EENV_DECISIONS*/
  
  #ifdef DEBUG_EENV_DECISIONS
  /* max of 8 levels of sched groups traversed */
  #define EAS_EENV_DEBUG_LEVELS 16
  
  struct _eenv_debug {
  	unsigned long cap;
  	unsigned long norm_util;
  	unsigned long cap_energy;
  	unsigned long idle_energy;
  	unsigned long this_energy;
  	unsigned long this_busy_energy;
  	unsigned long this_idle_energy;
  	cpumask_t group_cpumask;
  	unsigned long cpu_util[1];
  };
  #endif
  
  struct eenv_cpu {
  	/* CPU ID, must be in cpus_mask */
  	int     cpu_id;
  
  	/*
  	 * Index (into sched_group_energy::cap_states) of the OPP the
  	 * CPU needs to run at if the task is placed on it.
  	 * This includes the both active and blocked load, due to
  	 * other tasks on this CPU,  as well as the task's own
  	 * utilization.
  	*/
  	int     cap_idx;
  	int     cap;
  
  	/* Estimated system energy */
  	unsigned long energy;
  
  	/* Estimated energy variation wrt EAS_CPU_PRV */
  	long nrg_delta;
  
  #ifdef DEBUG_EENV_DECISIONS
  	struct _eenv_debug *debug;
  	int debug_idx;
  #endif /* DEBUG_EENV_DECISIONS */
  };
  
  struct energy_env {
  	/* Utilization to move */
  	struct task_struct	*p;
  	unsigned long		util_delta;
  	unsigned long		util_delta_boosted;
  
  	/* Mask of CPUs candidates to evaluate */
  	cpumask_t		cpus_mask;
  
  	/* CPU candidates to evaluate */
  	struct eenv_cpu *cpu;
  	int eenv_cpu_count;
  
  #ifdef DEBUG_EENV_DECISIONS
  	/* pointer to the memory block reserved
  	 * for debug on this CPU - there will be
  	 * sizeof(struct _eenv_debug) *
  	 *  (EAS_CPU_CNT * EAS_EENV_DEBUG_LEVELS)
  	 * bytes allocated here.
  	 */
  	struct _eenv_debug *debug;
  #endif
  	/*
  	 * Index (into energy_env::cpu) of the morst energy efficient CPU for
  	 * the specified energy_env::task
  	 */
  	int	next_idx;
  	int	max_cpu_count;
  
  	/* Support data */
  	struct sched_group	*sg_top;
  	struct sched_group	*sg_cap;
  	struct sched_group	*sg;
  #ifdef CONFIG_HISI_EAS_SCHED
  	int util_wake[NR_CPUS];
  #endif
  };
  
  /**
   * Amount of capacity of a CPU that is (estimated to be) used by CFS tasks
   * @cpu: the CPU to get the utilization of
   *
   * The unit of the return value must be the one of capacity so we can compare
   * the utilization with the capacity of the CPU that is available for CFS task
   * (ie cpu_capacity).
   *
   * cfs_rq.avg.util_avg is the sum of running time of runnable tasks plus the
   * recent utilization of currently non-runnable tasks on a CPU. It represents
   * the amount of utilization of a CPU in the range [0..capacity_orig] where
   * capacity_orig is the cpu_capacity available at the highest frequency,
   * i.e. arch_scale_cpu_capacity().
   * The utilization of a CPU converges towards a sum equal to or less than the
   * current capacity (capacity_curr <= capacity_orig) of the CPU because it is
   * the running time on this CPU scaled by capacity_curr.
   *
   * The estimated utilization of a CPU is defined to be the maximum between its
   * cfs_rq.avg.util_avg and the sum of the estimated utilization of the tasks
   * currently RUNNABLE on that CPU.
   * This allows to properly represent the expected utilization of a CPU which
   * has just got a big task running since a long sleep period. At the same time
   * however it preserves the benefits of the "blocked utilization" in
   * describing the potential for other tasks waking up on the same CPU.
   *
   * Nevertheless, cfs_rq.avg.util_avg can be higher than capacity_curr or even
   * higher than capacity_orig because of unfortunate rounding in
   * cfs.avg.util_avg or just after migrating tasks and new task wakeups until
   * the average stabilizes with the new running time. We need to check that the
   * utilization stays within the range of [0..capacity_orig] and cap it if
   * necessary. Without utilization capping, a group could be seen as overloaded
   * (CPU0 utilization at 121% + CPU1 utilization at 80%) whereas CPU1 has 20% of
   * available capacity. We allow utilization to overshoot capacity_curr (but not
   * capacity_orig) as it useful for predicting the capacity required after task
   * migrations (scheduler-driven DVFS).
   *
   * Return: the (estimated) utilization for the specified CPU
   */
  unsigned long cpu_util(int cpu)
  {
  	struct cfs_rq *cfs_rq;
  	unsigned int util;
  
  #ifdef CONFIG_SCHED_WALT
  	if (likely(!walt_disabled && sysctl_sched_use_walt_cpu_util)) {
  		u64 walt_cpu_util = cpu_rq(cpu)->cumulative_runnable_avg;
  
  		walt_cpu_util <<= SCHED_CAPACITY_SHIFT;
  		do_div(walt_cpu_util, walt_ravg_window);
  
  		return min_t(unsigned long, walt_cpu_util,
  			     capacity_orig_of(cpu));
  	}
  #endif
  
  	cfs_rq = &cpu_rq(cpu)->cfs;
  	util = READ_ONCE(cfs_rq->avg.util_avg);
  
  	if (sched_feat(UTIL_EST))
  		util = max(util, READ_ONCE(cfs_rq->avg.util_est.enqueued));
  
  	return min_t(unsigned long, util, capacity_orig_of(cpu));
  }
  
  static inline unsigned long cpu_util_rt(int cpu)
  {
  	struct rt_rq *rt_rq = &(cpu_rq(cpu)->rt);
  
  	return rt_rq->avg.util_avg;
  }
  
  unsigned long cpu_util_freq(int cpu)
  {
  #ifdef CONFIG_SCHED_WALT
  	u64 walt_cpu_util;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (unlikely(walt_disabled || !sysctl_sched_use_walt_cpu_util_freq)) {
  #else
  	if (unlikely(walt_disabled || !sysctl_sched_use_walt_cpu_util)) {
  #endif
  		return min(cpu_util(cpu) + cpu_util_rt(cpu),
  			   capacity_orig_of(cpu));
  	}
  
  	walt_cpu_util = cpu_rq(cpu)->prev_runnable_sum;
  	walt_cpu_util <<= SCHED_CAPACITY_SHIFT;
  	do_div(walt_cpu_util, walt_ravg_window);
  
  	return min_t(unsigned long, walt_cpu_util, capacity_orig_of(cpu));
  #else
  	return min(cpu_util(cpu) + cpu_util_rt(cpu), capacity_orig_of(cpu));
  #endif
  }
  
  /*
   * cpu_util_without: compute cpu utilization without any contributions from *p
   * @cpu: the CPU which utilization is requested
   * @p: the task which utilization should be discounted
   *
   * The utilization of a CPU is defined by the utilization of tasks currently
   * enqueued on that CPU as well as tasks which are currently sleeping after an
   * execution on that CPU.
   *
   * This method returns the utilization of the specified CPU by discounting the
   * utilization of the specified task, whenever the task is currently
   * contributing to the CPU utilization.
   */
  static unsigned long cpu_util_without(int cpu, struct task_struct *p)
  {
  	struct cfs_rq *cfs_rq;
  	unsigned int util;
  
  #ifdef CONFIG_SCHED_WALT
  	/*
  	 * WALT does not decay idle tasks in the same manner
  	 * as PELT, so it makes little sense to subtract task
  	 * utilization from cpu utilization. Instead just use
  	 * cpu_util for this case.
  	 */
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (likely(!walt_disabled && sysctl_sched_use_walt_cpu_util)) {
  		if (p->state == TASK_WAKING || cpu != task_cpu(p))
  			return cpu_util(cpu);
  
  		/* Task p is on this cpu's runqueue */
  		util = max_t(int, cpu_util(cpu) - task_util(p), 0);
  
  		return min_t(unsigned long, util, capacity_orig_of(cpu));
  	}
  #else
  	if (likely(!walt_disabled && sysctl_sched_use_walt_cpu_util))
  		return cpu_util(cpu);
  #endif
  #endif
  
  	/* Task has no contribution or is new */
  	if (cpu != task_cpu(p) || !READ_ONCE(p->se.avg.last_update_time))
  		return cpu_util(cpu);
  
  	cfs_rq = &cpu_rq(cpu)->cfs;
  	util = READ_ONCE(cfs_rq->avg.util_avg);
  
  	/* Discount task's util from CPU's util */
  	util -= min_t(unsigned int, util, task_util(p));
  
  	/*
  	 * Covered cases:
  	 *
  	 * a) if *p is the only task sleeping on this CPU, then:
  	 *      cpu_util (== task_util) > util_est (== 0)
  	 *    and thus we return:
  	 *      cpu_util_without = (cpu_util - task_util) = 0
  	 *
  	 * b) if other tasks are SLEEPING on this CPU, which is now exiting
  	 *    IDLE, then:
  	 *      cpu_util >= task_util
  	 *      cpu_util > util_est (== 0)
  	 *    and thus we discount *p's blocked utilization to return:
  	 *      cpu_util_without = (cpu_util - task_util) >= 0
  	 *
  	 * c) if other tasks are RUNNABLE on that CPU and
  	 *      util_est > cpu_util
  	 *    then we use util_est since it returns a more restrictive
  	 *    estimation of the spare capacity on that CPU, by just
  	 *    considering the expected utilization of tasks already
  	 *    runnable on that CPU.
  	 *
  	 * Cases a) and b) are covered by the above code, while case c) is
  	 * covered by the following code when estimated utilization is
  	 * enabled.
  	 */
  	if (sched_feat(UTIL_EST)) {
  		unsigned int estimated =
  			READ_ONCE(cfs_rq->avg.util_est.enqueued);
  
  		/*
  		 * Despite the following checks we still have a small window
  		 * for a possible race, when an execl's select_task_rq_fair()
  		 * races with LB's detach_task():
  		 *
  		 *   detach_task()
  		 *     p->on_rq = TASK_ON_RQ_MIGRATING;
  		 *     ---------------------------------- A
  		 *     deactivate_task()                   \
  		 *       dequeue_task()                     + RaceTime
  		 *         util_est_dequeue()              /
  		 *     ---------------------------------- B
  		 *
  		 * The additional check on "current == p" it's required to
  		 * properly fix the execl regression and it helps in further
  		 * reducing the chances for the above race.
  		 */
  		if (unlikely(task_on_rq_queued(p) || current == p)) {
  			estimated -= min_t(unsigned int, estimated,
  					   (_task_util_est(p) | UTIL_AVG_UNCHANGED));
  		}
  		util = max(util, estimated);
  	}
  
  	/*
  	 * Utilization (estimated) can exceed the CPU capacity, thus let's
  	 * clamp to the maximum CPU capacity to ensure consistency with
  	 * the cpu_util call.
  	 */
  	return min_t(unsigned long, util, capacity_orig_of(cpu));
  }
  
  static unsigned long group_max_util(struct energy_env *eenv, int cpu_idx)
  {
  	unsigned long max_util = 0;
  	unsigned long util;
  	int cpu;
  
  	for_each_cpu(cpu, sched_group_span(eenv->sg_cap)) {
  #ifdef CONFIG_HISI_EAS_SCHED
  		util = eenv->util_wake[cpu];
  #else
  		util = cpu_util_without(cpu, eenv->p);
  #endif
  
  		/*
  		 * If we are looking at the target CPU specified by the eenv,
  		 * then we should add the (estimated) utilization of the task
  		 * assuming we will wake it up on that CPU.
  		 */
  		if (unlikely(cpu == eenv->cpu[cpu_idx].cpu_id))
  			util += eenv->util_delta_boosted;
  
  		max_util = max(max_util, util);
  	}
  
  	return max_util;
  }
  
  /*
   * group_norm_util() returns the approximated group util relative to it's
   * current capacity (busy ratio) in the range [0..SCHED_CAPACITY_SCALE] for use
   * in energy calculations. Since task executions may or may not overlap in time
   * in the group the true normalized util is between max(cpu_norm_util(i)) and
   * sum(cpu_norm_util(i)) when iterating over all cpus in the group, i. The
   * latter is used as the estimate as it leads to a more pessimistic energy
   * estimate (more busy).
   */
  static unsigned
  long group_norm_util(struct energy_env *eenv, int cpu_idx)
  {
  	unsigned long capacity = eenv->cpu[cpu_idx].cap;
  	unsigned long util, util_sum = 0;
  	int cpu;
  
  	for_each_cpu(cpu, sched_group_span(eenv->sg)) {
  #ifdef CONFIG_HISI_EAS_SCHED
  		util = eenv->util_wake[cpu];
  #else
  		util = cpu_util_without(cpu, eenv->p);
  #endif
  
  		/*
  		 * If we are looking at the target CPU specified by the eenv,
  		 * then we should add the (estimated) utilization of the task
  		 * assuming we will wake it up on that CPU.
  		 */
  		if (unlikely(cpu == eenv->cpu[cpu_idx].cpu_id))
  			util += eenv->util_delta;
  
  		util_sum += __cpu_norm_util(util, capacity);
  	}
  
  	if (util_sum > SCHED_CAPACITY_SCALE)
  		return SCHED_CAPACITY_SCALE;
  	return util_sum;
  }
  
  static int find_new_capacity(struct energy_env *eenv, int cpu_idx)
  {
  #ifdef CONFIG_HISI_EAS_SCHED
  	const struct sched_group_energy *sge = eenv->sg->sge;
  #else
  	const struct sched_group_energy *sge = eenv->sg_cap->sge;
  #endif
  	unsigned long util = group_max_util(eenv, cpu_idx);
  	int idx, cap_idx;
  
  	cap_idx = sge->nr_cap_states - 1;
  
  	for (idx = 0; idx < sge->nr_cap_states; idx++) {
  		if (sge->cap_states[idx].cap >= util) {
  			cap_idx = idx;
  			break;
  		}
  	}
  	/* Keep track of SG's capacity */
  	eenv->cpu[cpu_idx].cap = sge->cap_states[cap_idx].cap;
  	eenv->cpu[cpu_idx].cap_idx = cap_idx;
  
  	return cap_idx;
  }
  
  static int group_idle_state(struct energy_env *eenv, int cpu_idx)
  {
  	struct sched_group *sg = eenv->sg;
  	int src_in_grp, dst_in_grp;
  	int i, state = INT_MAX;
  	int max_idle_state_idx;
  	long grp_util = 0;
  	int new_state;
  
  	/* Find the shallowest idle state in the sched group. */
  	for_each_cpu(i, sched_group_span(sg))
  		state = min(state, idle_get_state_idx(cpu_rq(i)));
  
  	/* Take non-cpuidle idling into account (active idle/arch_cpu_idle()) */
  	state++;
  #ifdef CONFIG_HISI_EAS_SCHED
  	return state;
  #endif
  	/*
  	 * Try to estimate if a deeper idle state is
  	 * achievable when we move the task.
  	 */
  	for_each_cpu(i, sched_group_span(sg))
  		grp_util += cpu_util(i);
  
  	src_in_grp = cpumask_test_cpu(eenv->cpu[EAS_CPU_PRV].cpu_id,
  				      sched_group_span(sg));
  	dst_in_grp = cpumask_test_cpu(eenv->cpu[cpu_idx].cpu_id,
  				      sched_group_span(sg));
  	if (src_in_grp == dst_in_grp) {
  		/*
  		 * both CPUs under consideration are in the same group or not in
  		 * either group, migration should leave idle state the same.
  		 */
  		return state;
  	}
  	/*
  	 * add or remove util as appropriate to indicate what group util
  	 * will be (worst case - no concurrent execution) after moving the task
  	 */
  	grp_util += src_in_grp ? -eenv->util_delta : eenv->util_delta;
  
  	if (grp_util >
  		((long)sg->sgc->max_capacity * (int)sg->group_weight)) {
  		/*
  		 * After moving, the group will be fully occupied
  		 * so assume it will not be idle at all.
  		 */
  		return 0;
  	}
  
  	/*
  	 * after moving, this group is at most partly
  	 * occupied, so it should have some idle time.
  	 */
  	max_idle_state_idx = sg->sge->nr_idle_states - 2;
  	new_state = grp_util * max_idle_state_idx;
  	if (grp_util <= 0) {
  		/* group will have no util, use lowest state */
  		new_state = max_idle_state_idx + 1;
  	} else {
  		/*
  		 * for partially idle, linearly map util to idle
  		 * states, excluding the lowest one. This does not
  		 * correspond to the state we expect to enter in
  		 * reality, but an indication of what might happen.
  		 */
  		new_state = min_t(int, max_idle_state_idx,
  				  new_state / sg->sgc->max_capacity);
  		new_state = max_idle_state_idx - new_state;
  	}
  	return new_state;
  }
  
  #ifdef DEBUG_EENV_DECISIONS
  static struct _eenv_debug *eenv_debug_entry_ptr(struct _eenv_debug *base, int idx);
  
  static void store_energy_calc_debug_info(struct energy_env *eenv, int cpu_idx, int cap_idx, int idle_idx)
  {
  	int debug_idx = eenv->cpu[cpu_idx].debug_idx;
  	unsigned long sg_util, busy_energy, idle_energy;
  	const struct sched_group_energy *sge;
  	struct _eenv_debug *dbg;
  	int cpu;
  
  	if (debug_idx < EAS_EENV_DEBUG_LEVELS) {
  		sge = eenv->sg->sge;
  		sg_util = group_norm_util(eenv, cpu_idx);
  		busy_energy   = sge->cap_states[cap_idx].power;
  		busy_energy  *= sg_util;
  		idle_energy   = SCHED_CAPACITY_SCALE - sg_util;
  		idle_energy  *= sge->idle_states[idle_idx].power;
  		/* should we use sg_cap or sg? */
  		dbg = eenv_debug_entry_ptr(eenv->cpu[cpu_idx].debug, debug_idx);
  		dbg->cap = sge->cap_states[cap_idx].cap;
  		dbg->norm_util = sg_util;
  		dbg->cap_energy = sge->cap_states[cap_idx].power;
  		dbg->idle_energy = sge->idle_states[idle_idx].power;
  		dbg->this_energy = busy_energy + idle_energy;
  		dbg->this_busy_energy = busy_energy;
  		dbg->this_idle_energy = idle_energy;
  
  		cpumask_copy(&dbg->group_cpumask,
  				sched_group_span(eenv->sg));
  
  		for_each_cpu(cpu, &dbg->group_cpumask)
  			dbg->cpu_util[cpu] = cpu_util(cpu);
  
  		eenv->cpu[cpu_idx].debug_idx = debug_idx+1;
  	}
  }
  #else
  #define store_energy_calc_debug_info(a,b,c,d) {}
  #endif /* DEBUG_EENV_DECISIONS */
  
  /*
   * calc_sg_energy: compute energy for the eenv's SG (i.e. eenv->sg).
   *
   * This works in iterations to compute the SG's energy for each CPU
   * candidate defined by the energy_env's cpu array.
   */
  static void calc_sg_energy(struct energy_env *eenv)
  {
  	struct sched_group *sg = eenv->sg;
  	unsigned long busy_energy, idle_energy;
  	unsigned int busy_power, idle_power;
  	unsigned long total_energy = 0;
  	unsigned long sg_util;
  	int cap_idx, idle_idx;
  	int cpu_idx;
  
  	for (cpu_idx = EAS_CPU_PRV; cpu_idx < eenv->max_cpu_count; ++cpu_idx) {
  		if (eenv->cpu[cpu_idx].cpu_id == -1)
  			continue;
  
  		/* Compute ACTIVE energy */
  		cap_idx = find_new_capacity(eenv, cpu_idx);
  		busy_power = sg->sge->cap_states[cap_idx].power;
  		sg_util = group_norm_util(eenv, cpu_idx);
  		busy_energy   = sg_util * busy_power;
  
  		/* Compute IDLE energy */
  		idle_idx = group_idle_state(eenv, cpu_idx);
  		idle_power = sg->sge->idle_states[idle_idx].power;
  #ifdef CONFIG_HISI_EAS_SCHED
  		/* If this idle state has power cost and we have idle power
  		 * assigned in the cap state, use the more accurate one. */
  		if (idle_power && sg->sge->cap_states[cap_idx].idle_power)
  			idle_power = sg->sge->cap_states[cap_idx].idle_power;
  #endif
  		idle_energy   = SCHED_CAPACITY_SCALE - sg_util;
  		idle_energy  *= idle_power;
  
  		total_energy = busy_energy + idle_energy;
  		eenv->cpu[cpu_idx].energy += total_energy;
  
  		store_energy_calc_debug_info(eenv, cpu_idx, cap_idx, idle_idx);
  
  #ifdef CONFIG_HISI_EAS_SCHED
  		trace_sched_group_energy(eenv->cpu[cpu_idx].cpu_id,
  					 sched_group_cpus(sg),
  					 idle_idx, cap_idx, sg_util,
  					 busy_energy >> SCHED_CAPACITY_SHIFT,
  					 idle_energy >> SCHED_CAPACITY_SHIFT);
  #endif
  	}
  }
  
  /*
   * compute_energy() computes the absolute variation in energy consumption by
   * moving eenv.util_delta from EAS_CPU_PRV to EAS_CPU_NXT.
   *
   * NOTE: compute_energy() may fail when racing with sched_domain updates, in
   *       which case we abort by returning -EINVAL.
   */
  static int compute_energy(struct energy_env *eenv)
  {
  	struct sched_domain *sd;
  	int cpu;
  	struct cpumask visit_cpus;
  	struct sched_group *sg;
  	int cpu_count;
  
  	WARN_ON(!eenv->sg_top->sge);
  
  	cpumask_copy(&visit_cpus, sched_group_span(eenv->sg_top));
  	/* If a cpu is hotplugged in while we are in this function, it does
  	 * not appear in the existing visit_cpus mask which came from the
  	 * sched_group pointer of the sched_domain pointed at by sd_ea for
  	 * either the prev or next cpu and was dereferenced in
  	 * select_energy_cpu_idx.
  	 * Since we will dereference sd_scs later as we iterate through the
  	 * CPUs we expect to visit, new CPUs can be present which are not in
  	 * the visit_cpus mask. Guard this with cpu_count.
  	 */
  	cpu_count = cpumask_weight(&visit_cpus);
  	while (!cpumask_empty(&visit_cpus)) {
  		struct sched_group *sg_shared_cap = NULL;
  
  		cpu = cpumask_first(&visit_cpus);
  
  		/*
  		 * Is the group utilization affected by cpus outside this
  		 * sched_group?
  		 * This sd may have groups with cpus which were not present
  		 * when we took visit_cpus.
  		 */
  		sd = rcu_dereference(per_cpu(sd_scs, cpu));
  		if (sd && sd->parent)
  			sg_shared_cap = sd->parent->groups;
  
  		for_each_domain(cpu, sd) {
  			sg = sd->groups;
  
  			/* Has this sched_domain already been visited? */
  			if (sd->child && group_first_cpu(sg) != cpu)
  				break;
  
  			do {
  				eenv->sg_cap = sg;
  				if (sg_shared_cap && sg_shared_cap->group_weight >= sg->group_weight)
  					eenv->sg_cap = sg_shared_cap;
  
  				/*
  				 * Compute the energy for all the candidate
  				 * CPUs in the current visited SG.
  				 */
  				eenv->sg = sg;
  				calc_sg_energy(eenv);
  
  				/* remove CPUs we have just visited */
  				if (!sd->child) {
  					/*
  					 * cpu_count here is the number of
  					 * cpus we expect to visit in this
  					 * calculation. If we race against
  					 * hotplug, we can have extra cpus
  					 * added to the groups we are
  					 * iterating which do not appear in
  					 * the visit_cpus mask. In that case
  					 * we are not able to calculate energy
  					 * without restarting so we will bail
  					 * out and use prev_cpu this time.
  					 */
  					if (!cpu_count)
  						return -EINVAL;
  					cpumask_xor(&visit_cpus, &visit_cpus, sched_group_span(sg));
  					cpu_count--;
  				}
  
  				if (cpumask_equal(sched_group_span(sg), sched_group_span(eenv->sg_top)) &&
  					sd->child)
  					goto next_cpu;
  
  			} while (sg = sg->next, sg != sd->groups);
  		}
  next_cpu:
  		cpumask_clear_cpu(cpu, &visit_cpus);
  		continue;
  	}
  
  	return 0;
  }
  
  static inline bool cpu_in_sg(struct sched_group *sg, int cpu)
  {
  	return cpu != -1 && cpumask_test_cpu(cpu, sched_group_span(sg));
  }
  
  #ifdef DEBUG_EENV_DECISIONS
  static void dump_eenv_debug(struct energy_env *eenv)
  {
  	int cpu_idx, grp_idx;
  	char cpu_utils[(NR_CPUS*12)+10]="cpu_util: ";
  	char cpulist[64];
  
  	trace_printk("eenv scenario: task=%p %s task_util=%lu prev_cpu=%d",
  			eenv->p, eenv->p->comm, eenv->util_delta, eenv->cpu[EAS_CPU_PRV].cpu_id);
  
  	for (cpu_idx=EAS_CPU_PRV; cpu_idx < eenv->max_cpu_count; cpu_idx++) {
  		if (eenv->cpu[cpu_idx].cpu_id == -1)
  			continue;
  		trace_printk("---Scenario %d: Place task on cpu %d energy=%lu (%d debug logs at %p)",
  				cpu_idx+1, eenv->cpu[cpu_idx].cpu_id,
  				eenv->cpu[cpu_idx].energy >> SCHED_CAPACITY_SHIFT,
  				eenv->cpu[cpu_idx].debug_idx,
  				eenv->cpu[cpu_idx].debug);
  		for (grp_idx = 0; grp_idx < eenv->cpu[cpu_idx].debug_idx; grp_idx++) {
  			struct _eenv_debug *debug;
  			int cpu, written=0;
  
  			debug = eenv_debug_entry_ptr(eenv->cpu[cpu_idx].debug, grp_idx);
  			cpu = scnprintf(cpulist, sizeof(cpulist), "%*pbl", cpumask_pr_args(&debug->group_cpumask));
  
  			cpu_utils[0] = 0;
  			/* print out the relevant cpu_util */
  			for_each_cpu(cpu, &(debug->group_cpumask)) {
  				char tmp[64];
  				if (written > sizeof(cpu_utils)-10) {
  					cpu_utils[written]=0;
  					break;
  				}
  				written += snprintf(tmp, sizeof(tmp), "cpu%d(%lu) ", cpu, debug->cpu_util[cpu]);
  				strcat(cpu_utils, tmp);
  			}
  			/* trace the data */
  			trace_printk("  | %s : cap=%lu nutil=%lu, cap_nrg=%lu, idle_nrg=%lu energy=%lu busy_energy=%lu idle_energy=%lu %s",
  					cpulist, debug->cap, debug->norm_util,
  					debug->cap_energy, debug->idle_energy,
  					debug->this_energy >> SCHED_CAPACITY_SHIFT,
  					debug->this_busy_energy >> SCHED_CAPACITY_SHIFT,
  					debug->this_idle_energy >> SCHED_CAPACITY_SHIFT,
  					cpu_utils);
  
  		}
  		trace_printk("---");
  	}
  	trace_printk("----- done");
  	return;
  }
  #else
  #define dump_eenv_debug(a) {}
  #endif /* DEBUG_EENV_DECISIONS */
  /*
   * select_energy_cpu_idx(): estimate the energy impact of changing the
   * utilization distribution.
   *
   * The eenv parameter specifies the changes: utilization amount and a
   * collection of possible CPU candidates. The number of candidates
   * depends upon the selection algorithm used.
   *
   * If find_best_target was used to select candidate CPUs, there will
   * be at most 3 including prev_cpu. If not, we used a brute force
   * selection which will provide the union of:
   *  * CPUs belonging to the highest sd which is not overutilized
   *  * CPUs the task is allowed to run on
   *  * online CPUs
   *
   * This function returns the index of a CPU candidate specified by the
   * energy_env which corresponds to the most energy efficient CPU.
   * Thus, 0 (EAS_CPU_PRV) means that non of the CPU candidate is more energy
   * efficient than running on prev_cpu. This is also the value returned in case
   * of abort due to error conditions during the computations. The only
   * exception to this if we fail to access the energy model via sd_ea, where
   * we return -1 with the intent of asking the system to use a different
   * wakeup placement algorithm.
   *
   * A value greater than zero means that the most energy efficient CPU is the
   * one represented by eenv->cpu[eenv->next_idx].cpu_id.
   */
  static inline int select_energy_cpu_idx(struct energy_env *eenv)
  {
  	int last_cpu_idx = eenv->max_cpu_count - 1;
  	struct sched_domain *sd;
  	struct sched_group *sg;
  	int sd_cpu = -1;
  	int cpu_idx;
  	int margin;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	/* Snapshot cpu_util_without */
  	for_each_possible_cpu(cpu_idx) {
  		eenv->util_wake[cpu_idx] = cpu_util_without(cpu_idx, eenv->p);
  	}
  
  	for (cpu_idx = EAS_CPU_NXT; cpu_idx < eenv->max_cpu_count; ++cpu_idx) {
  		/* No need for energy comparision if the candidate is prev_cpu */
  		if (eenv->cpu[cpu_idx].cpu_id == eenv->cpu[EAS_CPU_PRV].cpu_id)
  			eenv->cpu[cpu_idx].cpu_id = -1;
  	}
  #endif
  
  	sd_cpu = eenv->cpu[EAS_CPU_PRV].cpu_id;
  	sd = rcu_dereference(per_cpu(sd_ea, sd_cpu));
  	if (!sd)
  		return -1;
  
  	cpumask_clear(&eenv->cpus_mask);
  	for (cpu_idx = EAS_CPU_PRV; cpu_idx < eenv->max_cpu_count; ++cpu_idx) {
  		int cpu = eenv->cpu[cpu_idx].cpu_id;
  
  		if (cpu < 0)
  			continue;
  		cpumask_set_cpu(cpu, &eenv->cpus_mask);
  	}
  
  	sg = sd->groups;
  	do {
  		/* Skip SGs which do not contains a candidate CPU */
  		if (!cpumask_intersects(&eenv->cpus_mask, sched_group_span(sg)))
  			continue;
  
  		eenv->sg_top = sg;
  		if (compute_energy(eenv) == -EINVAL)
  			return EAS_CPU_PRV;
  	} while (sg = sg->next, sg != sd->groups);
  	/* remember - eenv energy values are unscaled */
  
  	/*
  	 * Compute the dead-zone margin used to prevent too many task
  	 * migrations with negligible energy savings.
  	 * An energy saving is considered meaningful if it reduces the energy
  	 * consumption of EAS_CPU_PRV CPU candidate by at least ~1.56%
  	 */
  	margin = eenv->cpu[EAS_CPU_PRV].energy >> 6;
  
  	/*
  	 * By default the EAS_CPU_PRV CPU is considered the most energy
  	 * efficient, with a 0 energy variation.
  	 */
  	eenv->next_idx = EAS_CPU_PRV;
  	eenv->cpu[EAS_CPU_PRV].nrg_delta = 0;
  
  	dump_eenv_debug(eenv);
  
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	trace_sched_energy_diff(eenv->p, eenv->cpu[EAS_CPU_PRV].cpu_id,
  				eenv->cpu[EAS_CPU_PRV].energy,
  				eenv->cpu[EAS_CPU_NXT].cpu_id,
  				eenv->cpu[EAS_CPU_NXT].energy,
  				eenv->cpu[EAS_CPU_BKP].cpu_id,
  				eenv->cpu[EAS_CPU_BKP].energy);
  #endif
  	/*
  	 * Compare the other CPU candidates to find a CPU which can be
  	 * more energy efficient then EAS_CPU_PRV
  	 */
  	if (sched_feat(FBT_STRICT_ORDER))
  		last_cpu_idx = EAS_CPU_BKP;
  
  	for(cpu_idx = EAS_CPU_NXT; cpu_idx <= last_cpu_idx; cpu_idx++) {
  		if (eenv->cpu[cpu_idx].cpu_id < 0)
  			continue;
  		eenv->cpu[cpu_idx].nrg_delta =
  			eenv->cpu[cpu_idx].energy -
  			eenv->cpu[EAS_CPU_PRV].energy;
  
  		/* filter energy variations within the dead-zone margin */
  		if (abs(eenv->cpu[cpu_idx].nrg_delta) < margin)
  			eenv->cpu[cpu_idx].nrg_delta = 0;
  		/* update the schedule candidate with min(nrg_delta) */
  		if (eenv->cpu[cpu_idx].nrg_delta <
  		    eenv->cpu[eenv->next_idx].nrg_delta) {
  			eenv->next_idx = cpu_idx;
  			/* break out if we want to stop on first saving candidate */
  			if (sched_feat(FBT_STRICT_ORDER))
  				break;
  		}
  #ifdef CONFIG_HISI_EAS_SCHED
  		if (eenv->cpu[cpu_idx].nrg_delta ==
  		    eenv->cpu[eenv->next_idx].nrg_delta) {
  			int this_cpu = eenv->cpu[cpu_idx].cpu_id;
  			int next_cpu = eenv->cpu[eenv->next_idx].cpu_id;
  
  			if (capacity_orig_of(this_cpu) < capacity_orig_of(next_cpu) ||
  			    (capacity_orig_of(this_cpu) == capacity_orig_of(next_cpu) &&
  			     eenv->util_wake[this_cpu] < eenv->util_wake[next_cpu])) {
  				eenv->next_idx = cpu_idx;
  				/* break out if we want to stop on first saving candidate */
  				if (sched_feat(FBT_STRICT_ORDER))
  					break;
  			}
  		}
  #endif
  	}
  
  	return eenv->next_idx;
  }
  
  #ifndef CONFIG_HISI_EAS_SCHED
  /*
   * Detect M:N waker/wakee relationships via a switching-frequency heuristic.
   *
   * A waker of many should wake a different task than the one last awakened
   * at a frequency roughly N times higher than one of its wakees.
   *
   * In order to determine whether we should let the load spread vs consolidating
   * to shared cache, we look for a minimum 'flip' frequency of llc_size in one
   * partner, and a factor of lls_size higher frequency in the other.
   *
   * With both conditions met, we can be relatively sure that the relationship is
   * non-monogamous, with partner count exceeding socket size.
   *
   * Waker/wakee being client/server, worker/dispatcher, interrupt source or
   * whatever is irrelevant, spread criteria is apparent partner count exceeds
   * socket size.
   */
  static int wake_wide(struct task_struct *p, int sibling_count_hint)
  {
  	unsigned int master = current->wakee_flips;
  	unsigned int slave = p->wakee_flips;
  	int llc_size = this_cpu_read(sd_llc_size);
  
  	if (sibling_count_hint >= llc_size)
  		return 1;
  
  	if (master < slave)
  		swap(master, slave);
  	if (slave < llc_size || master < slave * llc_size)
  		return 0;
  	return 1;
  }
  #endif
  
  /*
   * The purpose of wake_affine() is to quickly determine on which CPU we can run
   * soonest. For the purpose of speed we only consider the waking and previous
   * CPU.
   *
   * wake_affine_idle() - only considers 'now', it check if the waking CPU is (or
   *			will be) idle.
   *
   * wake_affine_weight() - considers the weight to reflect the average
   *			  scheduling latency of the CPUs. This seems to work
   *			  for the overloaded case.
   */
  
  static bool
  wake_affine_idle(struct sched_domain *sd, struct task_struct *p,
  		 int this_cpu, int prev_cpu, int sync)
  {
  	if (idle_cpu(this_cpu))
  		return true;
  
  	if (sync && cpu_rq(this_cpu)->nr_running == 1)
  		return true;
  
  	return false;
  }
  
  static bool
  wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
  		   int this_cpu, int prev_cpu, int sync)
  {
  	s64 this_eff_load, prev_eff_load;
  	unsigned long task_load;
  
  	this_eff_load = target_load(this_cpu, sd->wake_idx);
  	prev_eff_load = source_load(prev_cpu, sd->wake_idx);
  
  	if (sync) {
  		unsigned long current_load = task_h_load(current);
  
  		if (current_load > this_eff_load)
  			return true;
  
  		this_eff_load -= current_load;
  	}
  
  	task_load = task_h_load(p);
  
  	this_eff_load += task_load;
  	if (sched_feat(WA_BIAS))
  		this_eff_load *= 100;
  	this_eff_load *= capacity_of(prev_cpu);
  
  	prev_eff_load -= task_load;
  	if (sched_feat(WA_BIAS))
  		prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2;
  	prev_eff_load *= capacity_of(this_cpu);
  
  	return this_eff_load <= prev_eff_load;
  }
  
  static int wake_affine(struct sched_domain *sd, struct task_struct *p,
  		       int prev_cpu, int sync)
  {
  	int this_cpu = smp_processor_id();
  	bool affine = false;
  
  	if (sched_feat(WA_IDLE) && !affine)
  		affine = wake_affine_idle(sd, p, this_cpu, prev_cpu, sync);
  
  	if (sched_feat(WA_WEIGHT) && !affine)
  		affine = wake_affine_weight(sd, p, this_cpu, prev_cpu, sync);
  
  	schedstat_inc(p->se.statistics.nr_wakeups_affine_attempts);
  	if (affine) {
  		schedstat_inc(sd->ttwu_move_affine);
  		schedstat_inc(p->se.statistics.nr_wakeups_affine);
  	}
  
  	return affine;
  }
  
  #ifdef CONFIG_SCHED_TUNE
  struct reciprocal_value schedtune_spc_rdiv;
  
  long
  schedtune_margin(unsigned long signal, long boost)
  {
  	long long margin = 0;
  
  	/*
  	 * Signal proportional compensation (SPC)
  	 *
  	 * The Boost (B) value is used to compute a Margin (M) which is
  	 * proportional to the complement of the original Signal (S):
  	 *   M = B * (SCHED_CAPACITY_SCALE - S)
  	 * The obtained M could be used by the caller to "boost" S.
  	 */
  	if (boost >= 0) {
  		margin  = SCHED_CAPACITY_SCALE - signal;
  		margin *= boost;
  	} else
  		margin = -signal * boost;
  
  	margin  = reciprocal_divide(margin, schedtune_spc_rdiv);
  
  	if (boost < 0)
  		margin *= -1;
  	return margin;
  }
  
  static inline int
  schedtune_cpu_margin(unsigned long util, int cpu)
  {
  	int boost = schedtune_cpu_boost(cpu);
  
  	if (boost == 0)
  		return 0;
  
  	return schedtune_margin(util, boost);
  }
  
  #ifdef CONFIG_HISI_CPU_FREQ_GOV_SCHEDUTIL
  static inline int
  schedtune_freq_margin(unsigned long util, int cpu)
  {
  	int boost = schedtune_freq_boost(cpu);
  
  	if (boost == 0)
  		return 0;
  
  	return schedtune_margin(util, boost);
  }
  #endif
  
  static inline long
  schedtune_task_margin(struct task_struct *task)
  {
  	int boost = schedtune_task_boost(task);
  	unsigned long util;
  	long margin;
  
  	if (boost == 0)
  		return 0;
  
  	util = task_util_est(task);
  	margin = schedtune_margin(util, boost);
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (util + margin > task_boost_limit)
  		margin = max_t(int, task_boost_limit - util, 0);
  #endif
  
  	return margin;
  }
  #else /* CONFIG_SCHED_TUNE */
  
  static inline int
  schedtune_cpu_margin(unsigned long util, int cpu)
  {
  	return 0;
  }
  
  #ifdef CONFIG_HISI_CPU_FREQ_GOV_SCHEDUTIL
  static inline int
  schedtune_freq_margin(unsigned long util, int cpu)
  {
  	return 0;
  }
  #endif
  
  static inline long
  schedtune_task_margin(struct task_struct *task)
  {
  	return 0;
  }
  
  #endif /* CONFIG_SCHED_TUNE */
  
  unsigned long
  boosted_cpu_util(int cpu)
  {
  	unsigned long util = cpu_util_freq(cpu);
  	long margin = schedtune_cpu_margin(util, cpu);
  
  	trace_sched_boost_cpu(cpu, util, margin);
  
  	return util + margin;
  }
  
  #ifdef CONFIG_HISI_CPU_FREQ_GOV_SCHEDUTIL
  unsigned long
  freq_boosted(unsigned long util, int cpu)
  {
  	long margin = schedtune_freq_margin(util, cpu);
  
  	trace_sched_boost_cpu(cpu, util, margin);
  
  	return util + margin;
  }
  #endif
  
  #ifdef CONFIG_HISI_EAS_SCHED
  unsigned long
  boosted_task_util(struct task_struct *task)
  {
  	unsigned long util = task_util_est(task);
  	long margin = schedtune_task_margin(task);
  	unsigned long boosted_util = util + margin;
  
  	trace_sched_boost_task(task, util, margin);
  
  #ifdef CONFIG_SCHED_HISI_TASK_MIN_UTIL
  	boosted_util = max_t(unsigned long, boosted_util,
  				task->cpu_cap_req.min_util);
  #endif
  
  	return boosted_util;
  }
  #else
  static inline unsigned long
  boosted_task_util(struct task_struct *task)
  {
  	unsigned long util = task_util_est(task);
  	long margin = schedtune_task_margin(task);
  
  	trace_sched_boost_task(task, util, margin);
  
  	return util + margin;
  }
  #endif
  
  static unsigned long cpu_util_without(int cpu, struct task_struct *p);
  
  static unsigned long capacity_spare_without(int cpu, struct task_struct *p)
  {
  	return max_t(long, capacity_of(cpu) - cpu_util_without(cpu, p), 0);
  }
  
  /*
   * find_idlest_group finds and returns the least busy CPU group within the
   * domain.
   *
   * Assumes p is allowed on at least one CPU in sd.
   */
  static struct sched_group *
  find_idlest_group(struct sched_domain *sd, struct task_struct *p,
  		  int this_cpu, int sd_flag)
  {
  	struct sched_group *idlest = NULL, *group = sd->groups;
  	struct sched_group *most_spare_sg = NULL;
  	unsigned long min_runnable_load = ULONG_MAX;
  	unsigned long this_runnable_load = ULONG_MAX;
  	unsigned long min_avg_load = ULONG_MAX, this_avg_load = ULONG_MAX;
  	unsigned long most_spare = 0, this_spare = 0;
  	int load_idx = sd->forkexec_idx;
  	int imbalance_scale = 100 + (sd->imbalance_pct-100)/2;
  	unsigned long imbalance = scale_load_down(NICE_0_LOAD) *
  				(sd->imbalance_pct-100) / 100;
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_t allowed_cpus;
  
  	cpumask_andnot(&allowed_cpus, &p->cpus_allowed, cpu_isolated_mask);
  #endif
  
  
  	if (sd_flag & SD_BALANCE_WAKE)
  		load_idx = sd->wake_idx;
  
  	do {
  		unsigned long load, avg_load, runnable_load;
  		unsigned long spare_cap, max_spare_cap;
  		int local_group;
  		int i;
  
  		/* Skip over this group if it has no CPUs allowed */
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		if (!cpumask_intersects(sched_group_cpus(group),
  					&allowed_cpus))
  			continue;
  #else
  		if (!cpumask_intersects(sched_group_span(group),
  					&p->cpus_allowed))
  			continue;
  #endif
  
  		local_group = cpumask_test_cpu(this_cpu,
  					       sched_group_span(group));
  
  		/*
  		 * Tally up the load of all CPUs in the group and find
  		 * the group containing the CPU with most spare capacity.
  		 */
  		avg_load = 0;
  		runnable_load = 0;
  		max_spare_cap = 0;
  
  		for_each_cpu(i, sched_group_span(group)) {
  			/* Bias balancing toward cpus of our domain */
  			if (local_group)
  				load = source_load(i, load_idx);
  			else
  				load = target_load(i, load_idx);
  
  			runnable_load += load;
  
  			avg_load += cfs_rq_load_avg(&cpu_rq(i)->cfs);
  
  			spare_cap = capacity_spare_without(i, p);
  
  			if (spare_cap > max_spare_cap)
  				max_spare_cap = spare_cap;
  		}
  
  		/* Adjust by relative CPU capacity of the group */
  		if (group->sgc->capacity) {
  			avg_load = (avg_load * SCHED_CAPACITY_SCALE) /
  						group->sgc->capacity;
  			runnable_load = (runnable_load * SCHED_CAPACITY_SCALE) /
  						group->sgc->capacity;
  		}
  
  		if (local_group) {
  			this_runnable_load = runnable_load;
  			this_avg_load = avg_load;
  			this_spare = max_spare_cap;
  		} else {
  			if (min_runnable_load > (runnable_load + imbalance)) {
  				/*
  				 * The runnable load is significantly smaller
  				 * so we can pick this new cpu
  				 */
  				min_runnable_load = runnable_load;
  				min_avg_load = avg_load;
  				idlest = group;
  			} else if ((runnable_load < (min_runnable_load + imbalance)) &&
  				   (100*min_avg_load > imbalance_scale*avg_load)) {
  				/*
  				 * The runnable loads are close so take the
  				 * blocked load into account through avg_load.
  				 */
  				min_avg_load = avg_load;
  				idlest = group;
  			}
  
  			if (most_spare < max_spare_cap) {
  				most_spare = max_spare_cap;
  				most_spare_sg = group;
  			}
  		}
  	} while (group = group->next, group != sd->groups);
  
  	/*
  	 * The cross-over point between using spare capacity or least load
  	 * is too conservative for high utilization tasks on partially
  	 * utilized systems if we require spare_capacity > task_util(p),
  	 * so we allow for some task stuffing by using
  	 * spare_capacity > task_util(p)/2.
  	 *
  	 * Spare capacity can't be used for fork because the utilization has
  	 * not been set yet, we must first select a rq to compute the initial
  	 * utilization.
  	 */
  	if (sd_flag & SD_BALANCE_FORK)
  		goto skip_spare;
  
  	if (this_spare > task_util(p) / 2 &&
  	    imbalance_scale*this_spare > 100*most_spare)
  		return NULL;
  
  	if (most_spare > task_util(p) / 2)
  		return most_spare_sg;
  
  skip_spare:
  	if (!idlest)
  		return NULL;
  
  	if (min_runnable_load > (this_runnable_load + imbalance))
  		return NULL;
  
  	if ((this_runnable_load < (min_runnable_load + imbalance)) &&
  	     (100*this_avg_load < imbalance_scale*min_avg_load))
  		return NULL;
  
  	return idlest;
  }
  
  /*
   * find_idlest_group_cpu - find the idlest cpu among the cpus in group.
   */
  static int
  find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
  {
  	unsigned long load, min_load = ULONG_MAX;
  	unsigned int min_exit_latency = UINT_MAX;
  	u64 latest_idle_timestamp = 0;
  	int least_loaded_cpu = this_cpu;
  	int shallowest_idle_cpu = -1;
  	int i;
  
  	/* Check if we have any choice: */
  	if (group->group_weight == 1)
  		return cpumask_first(sched_group_span(group));
  
  	/* Traverse only the allowed CPUs */
  	for_each_cpu_and(i, sched_group_span(group), &p->cpus_allowed) {
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		if (cpu_isolated(i))
  			continue;
  #endif
  
  		if (idle_cpu(i)) {
  			struct rq *rq = cpu_rq(i);
  			struct cpuidle_state *idle = idle_get_state(rq);
  			if (idle && idle->exit_latency < min_exit_latency) {
  				/*
  				 * We give priority to a CPU whose idle state
  				 * has the smallest exit latency irrespective
  				 * of any idle timestamp.
  				 */
  				min_exit_latency = idle->exit_latency;
  				latest_idle_timestamp = rq->idle_stamp;
  				shallowest_idle_cpu = i;
  			} else if ((!idle || idle->exit_latency == min_exit_latency) &&
  				   rq->idle_stamp > latest_idle_timestamp) {
  				/*
  				 * If equal or no active idle state, then
  				 * the most recently idled CPU might have
  				 * a warmer cache.
  				 */
  				latest_idle_timestamp = rq->idle_stamp;
  				shallowest_idle_cpu = i;
  			}
  		} else if (shallowest_idle_cpu == -1) {
  			load = weighted_cpuload(cpu_rq(i));
  			if (load < min_load || (load == min_load && i == this_cpu)) {
  				min_load = load;
  				least_loaded_cpu = i;
  			}
  		}
  	}
  
  	return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu;
  }
  
  #ifdef CONFIG_HISI_EAS_SCHED
  #ifdef CONFIG_HISI_RTG
  static inline unsigned long
  spare_capacity(int cpu, struct task_struct *p)
  {
  	long spare;
  
  	spare = capacity_orig_of(cpu) - cpu_util_without(cpu, p);
  	if (unlikely(spare < 0))
  		spare = 0;
  
  	return (unsigned long)spare;
  }
  
  static inline int find_rtg_cpu(struct task_struct *p, struct cpumask *preferred_cpus)
  {
  	int i;
  	cpumask_t search_cpus = CPU_MASK_NONE;
  	int max_spare_cap_cpu =-1;
  	unsigned long max_spare_cap = 0;
  	int idle_backup_cpu = -1;
  
  	cpumask_and(&search_cpus, &p->cpus_allowed, cpu_online_mask);
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_andnot(&search_cpus, &search_cpus, cpu_isolated_mask);
  #endif
  
  	/* search the perferred idle cpu */
  	for_each_cpu_and(i, &search_cpus, preferred_cpus) {
  		if (is_reserved(i))
  			continue;
  
  		if (idle_cpu(i) || (i == task_cpu(p) && p->state == TASK_RUNNING)) {
  			trace_find_rtg_cpu(p, preferred_cpus, "prefer_idle", i);
  			return i;
  		}
  	}
  
  	for_each_cpu(i, &search_cpus) {
  		unsigned long spare_cap;
  
  		if (walt_cpu_high_irqload(i))
  			continue;
  
  		if (is_reserved(i))
  			continue;
  
  		/* take the Active LB CPU as idle_backup_cpu */
  		if (idle_cpu(i) || (i == task_cpu(p) && p->state == TASK_RUNNING)) {
  			/* find the idle_backup_cpu with max capacity */
  			if (idle_backup_cpu == -1 ||
  				capacity_orig_of(i) > capacity_orig_of(idle_backup_cpu))
  				idle_backup_cpu = i;
  
  			continue;
  		}
  
  		/* skip little cores for max_spare cpus */
  		if (hisi_test_slow_cpu(i))
  			continue;
  
  		spare_cap = spare_capacity(i, p);
  		if (spare_cap > max_spare_cap) {
  			max_spare_cap = spare_cap;
  			max_spare_cap_cpu = i;
  		}
  	}
  
  	if (idle_backup_cpu != -1) {
  		trace_find_rtg_cpu(p, preferred_cpus, "idle_backup", idle_backup_cpu);
  		return idle_backup_cpu;
  	}
  
  	trace_find_rtg_cpu(p, preferred_cpus, "max_spare", max_spare_cap_cpu);
  
  	return max_spare_cap_cpu;
  }
  #endif
  
  #ifdef CONFIG_SCHED_HISI_VIP
  int find_lowest_vip_cpu(struct task_struct *p,
  			struct cpumask *search_cpus)
  {
  	int i;
  	int target_cpu = -1;
  	unsigned int lowest_prio = p->hisi_vip_prio;
  	unsigned long max_cap = 0;
  	unsigned long min_util = ULONG_MAX;
  
  	for_each_cpu(i, search_cpus) {
  		unsigned int prio = cpu_rq(i)->highest_hisi_vip_prio;
  		unsigned long cap = capacity_orig_of(i);
  		unsigned long util = cpu_util_without(i, p);
  
  		if (p->state == TASK_RUNNING &&
  		    is_reserved(i))
  			continue;
  
  		if (prio > lowest_prio)
  			continue;
  
  		if (prio == lowest_prio) {
  			if (cap < max_cap)
  				continue;
  			if (cap == max_cap &&
  			    util >= min_util)
  				continue;
  		}
  
  		lowest_prio = prio;
  		max_cap = cap;
  		min_util = util;
  		target_cpu = i;
  	}
  
  	return target_cpu;
  }
  
  static int find_vip_cpu(struct task_struct *p)
  {
  	int i;
  	int target_cpu = -1;
  	int preferred_cpu = -1;
  	cpumask_t search_cpus = CPU_MASK_NONE;
  	cpumask_t preferred_cluster_cpus = CPU_MASK_NONE;
  	bool favor_larger_capacity = false;
  	unsigned long capacity_orig, wake_util;
  	int idle_idx;
  	int best_idle_cstate = INT_MAX;
  	unsigned long min_wake_util = ULONG_MAX;
  	unsigned long target_capacity = ULONG_MAX;
  	struct related_thread_group *grp = NULL;
  
  #ifdef CONFIG_HISI_RTG
  	rcu_read_lock();
  	grp = task_related_thread_group(p);
  	if (grp && grp->preferred_cluster) {
  		cpumask_copy(&preferred_cluster_cpus,
  				&grp->preferred_cluster->cpus);
  		favor_larger_capacity = true;
  	}
  	rcu_read_unlock();
  #endif
  
  	if (global_boost_enable && schedtune_task_boost(p) > 0)
  		favor_larger_capacity = true;
  
  	if (favor_larger_capacity)
  		target_capacity = 0;
  
  	cpumask_and(&search_cpus, &p->cpus_allowed, cpu_online_mask);
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_andnot(&search_cpus, &search_cpus, cpu_isolated_mask);
  #endif
  
  	for_each_cpu(i, &search_cpus) {
  		trace_sched_find_vip_cpu_each(
  			p, i, !list_empty(&cpu_rq(i)->hisi_vip_thread_list),
  			cpu_rq(i)->highest_hisi_vip_prio, is_reserved(i),
  			walt_cpu_high_irqload(i), capacity_orig_of(i),
  			cpu_util_without(i, p),
  			cpumask_test_cpu(i, &preferred_cluster_cpus)
  		);
  
  		if (!list_empty(&cpu_rq(i)->hisi_vip_thread_list))
  			continue;
  
  		if (is_reserved(i))
  			continue;
  
  		if (walt_cpu_high_irqload(i))
  			continue;
  
  		capacity_orig = capacity_orig_of(i);
  		wake_util = cpu_util_without(i, p);
  		idle_idx = idle_cpu(i) ? idle_get_state_idx(cpu_rq(i))
  					: INT_MAX;
  
  		if (cpumask_test_cpu(i, &preferred_cluster_cpus)) {
  			if (preferred_cpu != -1) {
  				/*
  				 * In preferred cluster, favor lowest
  				 * wake util cpu or shallowest idle cpu.
  				 */
  				if (wake_util > min_wake_util)
  					continue;
  
  				if (idle_idx >= best_idle_cstate)
  					continue;
  			}
  
  			preferred_cpu = i;
  			min_wake_util = wake_util;
  			best_idle_cstate = idle_idx;
  		}
  
  		if (preferred_cpu != -1)
  			continue;
  
  		if (!task_fits_max(p, i))
  			continue;
  
  		/* Favor larger/smaller capacity cpu when possible. */
  		if (favor_larger_capacity) {
  			if (capacity_orig < target_capacity)
  				continue;
  		} else {
  			if (capacity_orig > target_capacity)
  				continue;
  		}
  
  		if (capacity_orig == target_capacity) {
  			/*
  			 * In same cluster, favor lowest wake util
  			 * cpu or shallowest idle cpu.
  			 */
  			if (wake_util > min_wake_util)
  				continue;
  
  			if (idle_idx >= best_idle_cstate)
  				continue;
  		}
  
  		target_cpu = i;
  		target_capacity = capacity_orig;
  		min_wake_util = wake_util;
  		best_idle_cstate = idle_idx;
  	}
  
  	if (preferred_cpu != -1)
  		target_cpu = preferred_cpu;
  
  	/*
  	 * If we didn't find a suitable non-vip cpu, try to find a cpu
  	 * with lowest vip prio and do not consider power efficiency.
  	 */
  	if (target_cpu == -1)
  		target_cpu = find_lowest_vip_cpu(p, &search_cpus);
  
  	trace_sched_find_vip_cpu(p, preferred_cpu,
  			favor_larger_capacity, target_cpu);
  	return target_cpu;
  }
  #endif
  
  /*
   * find_boost_cpu - find the idlest cpu among the fast_cpus.
   */
  static int
  find_boost_cpu(struct cpumask *group_cpus, struct task_struct *p, int this_cpu)
  {
  	unsigned long load, min_load = ULONG_MAX;
  	unsigned int min_exit_latency = UINT_MAX;
  	u64 latest_idle_timestamp = 0;
  	int least_loaded_cpu = this_cpu;
  	int shallowest_idle_cpu = -1;
  	int i;
  
  	rcu_read_lock();
  	/* Traverse only the allowed CPUs */
  	for_each_cpu_and(i, group_cpus, &p->cpus_allowed) {
  		if (!cpumask_test_cpu(i, cpu_online_mask))
  			continue;
  
  		if (idle_cpu(i)) {
  			struct rq *rq = cpu_rq(i);
  			struct cpuidle_state *idle = idle_get_state(rq);
  			if (idle && idle->exit_latency < min_exit_latency) {
  				/*
  				 * We give priority to a CPU whose idle state
  				 * has the smallest exit latency irrespective
  				 * of any idle timestamp.
  				 */
  				min_exit_latency = idle->exit_latency;
  				latest_idle_timestamp = rq->idle_stamp;
  				shallowest_idle_cpu = i;
  			} else if ((!idle || idle->exit_latency == min_exit_latency) &&
  				   rq->idle_stamp > latest_idle_timestamp) {
  				/*
  				 * If equal or no active idle state, then
  				 * the most recently idled CPU might have
  				 * a warmer cache.
  				 */
  				latest_idle_timestamp = rq->idle_stamp;
  				shallowest_idle_cpu = i;
  			}
  		} else {
  			load = weighted_cpuload(cpu_rq(i));
  			if (load < min_load || (load == min_load && i == this_cpu)) {
  				min_load = load;
  				least_loaded_cpu = i;
  			}
  		}
  	}
  
  	rcu_read_unlock();
  	return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu;
  }
  
  #ifndef CONFIG_HISI_MULTI_MARGIN
  static unsigned long cpu_spare_capacity(int cpu, unsigned long util)
  {
  	unsigned long spare_capacity;
  	spare_capacity = capacity_of(cpu) - util;
  	spare_capacity = clamp(spare_capacity, 0UL, capacity_of(cpu));
  
  	return spare_capacity;
  }
  
  static inline bool __task_fits(struct task_struct *p, int cpu, int util)
  {
  	unsigned long capacity = capacity_of(cpu);
  
  	util += boosted_task_util(p);
  
  	return (capacity * 1024) > (util * hisi_capacity_margin(cpu));
  }
  static int
  find_spare_boost_cpu(struct cpumask *group_cpus, struct task_struct *p)
  {
  	int spare_boost_cpu = -1;
  	unsigned long max_spare_capacity = 0;
  	unsigned long spare_capacity;
  	int i;
  	int spare_idle_cpu = -1;
  	unsigned long max_idle_cap = 0;
  	unsigned long wake_util;
  
  	for_each_cpu_and(i, group_cpus, &p->cpus_allowed) {
  		/* If the CPU's utilizaiton is over 60%,
  		 * then we don't consider the cpu as spare one.
  		 */
  		wake_util = cpu_util_without(i, p);
  		if (!__task_fits(p, i, cpu_util(i)))
  			continue;
  
  		spare_capacity = cpu_spare_capacity(i, wake_util);
  		if (idle_cpu(i)) {
  			if (spare_idle_cpu != i && spare_capacity > max_idle_cap) {
  				spare_idle_cpu = i;
  				max_idle_cap = spare_capacity;
  			}
  		} else {
  			if (spare_capacity > max_spare_capacity) {
  				max_spare_capacity = spare_capacity;
  				spare_boost_cpu = i;
  			}
  		}
  		
  	}
  
  	spare_boost_cpu = (spare_idle_cpu != -1) ? spare_idle_cpu : spare_boost_cpu;
  
  	return spare_boost_cpu;
  }
  
  static int select_boost_cpu(struct task_struct *p, int spare_cpu, int boost_cpu)
  {
  	unsigned long cap_boost_cpu, cap_spare_cpu;
  
  	cap_boost_cpu = cpu_spare_capacity(boost_cpu, cpu_util_without(boost_cpu, p));
  	cap_spare_cpu = cpu_spare_capacity(spare_cpu, cpu_util_without(spare_cpu, p));
  
  
  	/* select the cpu with max spare cap */
  	if (cap_boost_cpu < cap_spare_cpu)
  		boost_cpu = spare_cpu;
  
  	return boost_cpu;
  }
  
  static int
  find_global_boost_cpu(struct task_struct *p)
  {
  	struct cpumask fast_cpus;
  	struct cpumask spare_cpus;
  	int boost_cpu = -1;
  	int spare_cpu = -1;
  
  
  	hisi_get_fast_cpus(&fast_cpus);
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_andnot(&fast_cpus, &fast_cpus, cpu_isolated_mask);
  #endif
  
  	if (cpumask_empty(&fast_cpus) || !cpumask_intersects(&p->cpus_allowed, &fast_cpus)
  	    || !cpumask_intersects(&fast_cpus, cpu_online_mask))
  		return -1;
  
  	boost_cpu = find_boost_cpu(&fast_cpus, p, cpumask_first(&fast_cpus));
  	if (boost_cpu != -1) {
  		if (idle_cpu(boost_cpu))
  		    return boost_cpu;
  
  		/* Enable spare boost cpu feature */
  		/* If util of boost_cpu is over 90%, check if any spare cpu is available.*/
  		if ((capacity_of(boost_cpu) * 1024) < (cpu_util_without(boost_cpu, p) * 1138)) {
  			cpumask_xor(&spare_cpus, &fast_cpus, cpu_online_mask);
  #ifdef CONFIG_HISI_CPU_ISOLATION
  			cpumask_andnot(&spare_cpus, &spare_cpus, cpu_isolated_mask);
  #endif
  			spare_cpu = find_spare_boost_cpu(&spare_cpus, p);
  
  			/* if spare_cpu available, select max spare one . */
  			if (spare_cpu != -1)
  				boost_cpu= select_boost_cpu(p, spare_cpu, boost_cpu);
  
  		}
  	}
  
  	return boost_cpu;
  }
  #else /* CONFIG_HISI_MULTI_MARGIN */
  static int
  find_global_boost_cpu(struct task_struct *p)
  {
  	int boost_cpu = -1;
  	struct sched_cluster *cluster;
  
  	for_each_sched_cluster_reverse(cluster) {
  		boost_cpu = find_boost_cpu(&cluster->cpus, p, cpumask_first(&cluster->cpus));
  		if (boost_cpu == -1)
  			continue;
  
  		if (idle_cpu(boost_cpu))
  			break;
  
  		/* If util of boost_cpu is over 90%, check other cluster.*/
  		if ((capacity_of(boost_cpu) * 1024) >= (cpu_util_without(boost_cpu, p) * 1138))
  			break;
  	}
  
  	return boost_cpu;
  }
  #endif /* CONFIG_HISI_MULTI_MARGIN */
  #endif
  
  static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p,
  				  int cpu, int prev_cpu, int sd_flag)
  {
  	int new_cpu = cpu;
  
  	if (!cpumask_intersects(sched_domain_span(sd), &p->cpus_allowed))
  		return prev_cpu;
  
  	while (sd) {
  		struct sched_group *group;
  		struct sched_domain *tmp;
  		int weight;
  
  		if (!(sd->flags & sd_flag)) {
  			sd = sd->child;
  			continue;
  		}
  
  		group = find_idlest_group(sd, p, cpu, sd_flag);
  		if (!group) {
  			sd = sd->child;
  			continue;
  		}
  
  		new_cpu = find_idlest_group_cpu(group, p, cpu);
  		if (new_cpu == cpu) {
  			/* Now try balancing at a lower domain level of cpu */
  			sd = sd->child;
  			continue;
  		}
  
  		/* Now try balancing at a lower domain level of new_cpu */
  		cpu = new_cpu;
  		weight = sd->span_weight;
  		sd = NULL;
  		for_each_domain(cpu, tmp) {
  			if (weight <= tmp->span_weight)
  				break;
  			if (tmp->flags & sd_flag)
  				sd = tmp;
  		}
  		/* while loop will break here if sd == NULL */
  	}
  
  	return new_cpu;
  }
  
  #ifdef CONFIG_SCHED_SMT
  DEFINE_STATIC_KEY_FALSE(sched_smt_present);
  EXPORT_SYMBOL_GPL(sched_smt_present);
  
  static inline void set_idle_cores(int cpu, int val)
  {
  	struct sched_domain_shared *sds;
  
  	sds = rcu_dereference(per_cpu(sd_llc_shared, cpu));
  	if (sds)
  		WRITE_ONCE(sds->has_idle_cores, val);
  }
  
  static inline bool test_idle_cores(int cpu, bool def)
  {
  	struct sched_domain_shared *sds;
  
  	sds = rcu_dereference(per_cpu(sd_llc_shared, cpu));
  	if (sds)
  		return READ_ONCE(sds->has_idle_cores);
  
  	return def;
  }
  
  /*
   * Scans the local SMT mask to see if the entire core is idle, and records this
   * information in sd_llc_shared->has_idle_cores.
   *
   * Since SMT siblings share all cache levels, inspecting this limited remote
   * state should be fairly cheap.
   */
  void __update_idle_core(struct rq *rq)
  {
  	int core = cpu_of(rq);
  	int cpu;
  
  	rcu_read_lock();
  	if (test_idle_cores(core, true))
  		goto unlock;
  
  	for_each_cpu(cpu, cpu_smt_mask(core)) {
  		if (cpu == core)
  			continue;
  
  		if (!idle_cpu(cpu))
  			goto unlock;
  	}
  
  	set_idle_cores(core, 1);
  unlock:
  	rcu_read_unlock();
  }
  
  /*
   * Scan the entire LLC domain for idle cores; this dynamically switches off if
   * there are no idle cores left in the system; tracked through
   * sd_llc->shared->has_idle_cores and enabled through update_idle_core() above.
   */
  static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int target)
  {
  	struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask);
  	int core, cpu;
  
  	if (!static_branch_likely(&sched_smt_present))
  		return -1;
  
  	if (!test_idle_cores(target, false))
  		return -1;
  
  	cpumask_and(cpus, sched_domain_span(sd), &p->cpus_allowed);
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_andnot(cpus, cpus, cpu_isolated_mask);
  #endif
  
  	for_each_cpu_wrap(core, cpus, target) {
  		bool idle = true;
  
  		for_each_cpu(cpu, cpu_smt_mask(core)) {
  			cpumask_clear_cpu(cpu, cpus);
  			if (!idle_cpu(cpu))
  				idle = false;
  		}
  
  		if (idle)
  			return core;
  	}
  
  	/*
  	 * Failed to find an idle core; stop looking for one.
  	 */
  	set_idle_cores(target, 0);
  
  	return -1;
  }
  
  /*
   * Scan the local SMT mask for idle CPUs.
   */
  static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target)
  {
  	int cpu;
  
  	if (!static_branch_likely(&sched_smt_present))
  		return -1;
  
  	for_each_cpu(cpu, cpu_smt_mask(target)) {
  		if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
  			continue;
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		if (cpu_isolated(cpu))
  			continue;
  #endif
  		if (idle_cpu(cpu))
  			return cpu;
  	}
  
  	return -1;
  }
  
  #else /* CONFIG_SCHED_SMT */
  
  static inline int select_idle_core(struct task_struct *p, struct sched_domain *sd, int target)
  {
  	return -1;
  }
  
  static inline int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int target)
  {
  	return -1;
  }
  
  #endif /* CONFIG_SCHED_SMT */
  
  /*
   * Scan the LLC domain for idle CPUs; this is dynamically regulated by
   * comparing the average scan cost (tracked in sd->avg_scan_cost) against the
   * average idle time for this rq (as found in rq->avg_idle).
   */
  static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int target)
  {
  	struct sched_domain *this_sd;
  	u64 avg_cost, avg_idle;
  	u64 time, cost;
  	s64 delta;
  	int cpu, nr = INT_MAX;
  
  	this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc));
  	if (!this_sd)
  		return -1;
  
  	/*
  	 * Due to large variance we need a large fuzz factor; hackbench in
  	 * particularly is sensitive here.
  	 */
  	avg_idle = this_rq()->avg_idle / 512;
  	avg_cost = this_sd->avg_scan_cost + 1;
  
  	if (sched_feat(SIS_AVG_CPU) && avg_idle < avg_cost)
  		return -1;
  
  	if (sched_feat(SIS_PROP)) {
  		u64 span_avg = sd->span_weight * avg_idle;
  		if (span_avg > 4*avg_cost)
  			nr = div_u64(span_avg, avg_cost);
  		else
  			nr = 4;
  	}
  
  	time = local_clock();
  
  	for_each_cpu_wrap(cpu, sched_domain_span(sd), target) {
  		if (!--nr)
  			return -1;
  		if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
  			continue;
  		if (idle_cpu(cpu))
  			break;
  	}
  
  	time = local_clock() - time;
  	cost = this_sd->avg_scan_cost;
  	delta = (s64)(time - cost) / 8;
  	this_sd->avg_scan_cost += delta;
  
  	return cpu;
  }
  
  /*
   * Try and locate an idle core/thread in the LLC cache domain.
   */
  static inline int __select_idle_sibling(struct task_struct *p, int prev, int target)
  {
  	struct sched_domain *sd;
  	int i;
  
  	if (idle_cpu(target))
  		return target;
  
  	/*
  	 * If the previous cpu is cache affine and idle, don't be stupid.
  	 */
  	if (prev != target && cpus_share_cache(prev, target) && idle_cpu(prev))
  		return prev;
  
  	sd = rcu_dereference(per_cpu(sd_llc, target));
  	if (!sd)
  		return target;
  
  	i = select_idle_core(p, sd, target);
  	if ((unsigned)i < nr_cpumask_bits)
  		return i;
  
  	i = select_idle_cpu(p, sd, target);
  	if ((unsigned)i < nr_cpumask_bits)
  		return i;
  
  	i = select_idle_smt(p, sd, target);
  	if ((unsigned)i < nr_cpumask_bits)
  		return i;
  
  	return target;
  }
  
  static inline int select_idle_sibling_cstate_aware(struct task_struct *p, int prev, int target)
  {
  	struct sched_domain *sd;
  	struct sched_group *sg;
  	int best_idle_cpu = -1;
  	int best_idle_cstate = -1;
  	int best_idle_capacity = INT_MAX;
  	int i;
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	struct cpumask allowed_cpus;
  #endif
  
  	/*
  	 * Iterate the domains and find an elegible idle cpu.
  	 */
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_andnot(&allowed_cpus, &p->cpus_allowed, cpu_isolated_mask);
  #endif
  	sd = rcu_dereference(per_cpu(sd_llc, target));
  	for_each_lower_domain(sd) {
  		sg = sd->groups;
  		do {
  #ifdef CONFIG_HISI_CPU_ISOLATION
  			if (!cpumask_intersects(sched_group_cpus(sg),
  						&allowed_cpus))
  				goto next;
  #else
  			if (!cpumask_intersects(
  					sched_group_span(sg), &p->cpus_allowed))
  				goto next;
  #endif
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  			for_each_cpu_and(i, &allowed_cpus, sched_group_cpus(sg)) {
  #else
  			for_each_cpu_and(i, &p->cpus_allowed, sched_group_span(sg)) {
  #endif
  				int idle_idx;
  				unsigned long new_usage;
  				unsigned long capacity_orig;
  
  				if (!idle_cpu(i))
  					goto next;
  
  				/* figure out if the task can fit here at all */
  				new_usage = boosted_task_util(p);
  				capacity_orig = capacity_orig_of(i);
  
  				if (new_usage > capacity_orig)
  					goto next;
  
  				/* if the task fits without changing OPP and we
  				 * intended to use this CPU, just proceed
  				 */
  				if (i == target && new_usage <= capacity_curr_of(target)) {
  					return target;
  				}
  
  				/* otherwise select CPU with shallowest idle state
  				 * to reduce wakeup latency.
  				 */
  				idle_idx = idle_get_state_idx(cpu_rq(i));
  
  				if (idle_idx < best_idle_cstate &&
  					capacity_orig <= best_idle_capacity) {
  					best_idle_cpu = i;
  					best_idle_cstate = idle_idx;
  					best_idle_capacity = capacity_orig;
  				}
  			}
  	next:
  			sg = sg->next;
  		} while (sg != sd->groups);
  	}
  
  	if (best_idle_cpu >= 0)
  		target = best_idle_cpu;
  
  	return target;
  }
  
  /*Ian flow modify have note __select_idle_sibling*/
  static int select_idle_sibling(struct task_struct *p, int prev, int target)
  {
  	if (!sysctl_sched_cstate_aware)
  		return __select_idle_sibling(p, prev, target);
  
  	return select_idle_sibling_cstate_aware(p, prev, target);
  }
  
  #ifndef CONFIG_HISI_EAS_SCHED
  static inline int task_fits_capacity(struct task_struct *p, long capacity)
  {
  	return capacity * 1024 > boosted_task_util(p) * capacity_margin;
  }
  #endif
  
  static int start_cpu(bool boosted)
  {
  	struct root_domain *rd = cpu_rq(smp_processor_id())->rd;
  	return boosted ? rd->max_cap_orig_cpu : rd->min_cap_orig_cpu;
  }
  
  #ifdef CONFIG_HISI_EAS_SCHED
  static inline bool hisi_favor_smaller_capacity(struct task_struct *p, int cpu)
  {
  	if (test_tsk_thread_flag(p, TIF_FAVOR_SMALL_CAP))
  		return true;
  
  	return (boosted_task_util(p) * 100) <
  		(capacity_orig_of(cpu) * up_migration_util_filter);
  }
  
  static inline bool skip_cpu(int cpu)
  {
  	/* Check all conditions other than util here. */
  	return !cpu_online(cpu) ||
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	       cpu_isolated(cpu) ||
  #endif
  	       walt_cpu_high_irqload(cpu) ||
  	       is_reserved(cpu);
  }
  #endif
  
  static inline int find_best_target(struct task_struct *p, int *backup_cpu,
  				   bool boosted, bool prefer_idle)
  {
  	unsigned long min_util = boosted_task_util(p);
  	unsigned long target_capacity = ULONG_MAX;
  	unsigned long min_wake_util = ULONG_MAX;
  	unsigned long target_max_spare_cap = 0;
  	unsigned long target_util = ULONG_MAX;
  	unsigned long best_active_util = ULONG_MAX;
  	int best_idle_cstate = INT_MAX;
  	struct sched_domain *sd;
  	struct sched_group *sg;
  	int best_active_cpu = -1;
  	int best_idle_cpu = -1;
  	int target_cpu = -1;
  	int cpu, i;
  #ifdef CONFIG_HISI_EAS_SCHED
  	bool favor_smaller_capacity = false;
  	unsigned long min_cap_orig = ULONG_MAX;
  #endif
  
  	*backup_cpu = -1;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	/*
  	 * Use boosted logic in fbt when global_boost_enable.
  	 */
  	boosted = boosted && global_boost_enable;
  
  	/*
  	 * We look for a high performance CPU for boosted tasks, including
  	 * prefer_idle or !prefer_idle ones.
  	 */
  	if (boosted)
  		target_capacity = 0;
  #else
  	/*
  	 * In most cases, target_capacity tracks capacity_orig of the most
  	 * energy efficient CPU candidate, thus requiring to minimise
  	 * target_capacity. For these cases target_capacity is already
  	 * initialized to ULONG_MAX.
  	 * However, for prefer_idle and boosted tasks we look for a high
  	 * performance CPU, thus requiring to maximise target_capacity. In this
  	 * case we initialise target_capacity to 0.
  	 */
  	if (prefer_idle && boosted)
  		target_capacity = 0;
  #endif
  
  	/* Find start CPU based on boost value */
  	cpu = start_cpu(boosted);
  	if (cpu < 0)
  		return -1;
  
  	/* Find SD for the start CPU */
  	sd = rcu_dereference(per_cpu(sd_ea, cpu));
  	if (!sd)
  		return -1;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (prefer_idle && !boosted) {
  		favor_smaller_capacity = hisi_favor_smaller_capacity(p, cpu);
  	}
  #endif
  
  	/* Scan CPUs in all SDs */
  	sg = sd->groups;
  	do {
  		for_each_cpu_and(i, &p->cpus_allowed, sched_group_span(sg)) {
  			unsigned long capacity_curr = capacity_curr_of(i);
  			unsigned long capacity_orig = capacity_orig_of(i);
  			unsigned long wake_util, new_util, min_capped_util;
  			long spare_cap;
  			int idle_idx = INT_MAX;
  
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  			trace_sched_cpu_util(i, cpu_util_without(i, p) + task_util_est(p),
  					     walt_irqload(i),
  					     walt_cpu_high_irqload(i),
  					     capacity_curr_of(i),
  					     capacity_of(i),
  					     capacity_orig_of(i),
  					     capacity_min_of(i));
  #endif
  
  #ifdef CONFIG_HISI_EAS_SCHED
  			if (skip_cpu(i))
  				continue;
  #else
  			if (!cpu_online(i))
  				continue;
  
  			if (walt_cpu_high_irqload(i))
  				continue;
  #endif
  
  			/*
  			 * p's blocked utilization is still accounted for on prev_cpu
  			 * so prev_cpu will receive a negative bias due to the double
  			 * accounting. However, the blocked utilization may be zero.
  			 */
  			wake_util = cpu_util_without(i, p);
  			new_util = wake_util + task_util_est(p);
  
  			/*
  			 * Consider the boosted_task_util() in task_fits_max().
  			 */
  #ifndef CONFIG_HISI_EAS_SCHED
  			/*
  			 * Ensure minimum capacity to grant the required boost.
  			 * The target CPU can be already at a capacity level higher
  			 * than the one required to boost the task.
  			 */
  			new_util = max(min_util, new_util);
  #endif
  
  			/*
  			 * Include minimum capacity constraint:
  			 * new_util contains the required utilization including
  			 * boost. min_capped_util also takes into account a
  			 * minimum capacity cap imposed on the CPU by external
  			 * actors.
  			 */
  			min_capped_util = max(new_util, capacity_min_of(i));
  
  			if (new_util > capacity_orig)
  				continue;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  			if (!task_fits_max(p, i))
  				continue;
  
  			if (!idle_cpu(i)) {
  #ifdef CONFIG_SCHED_HISI_USE_WALT
  				/*
  				 * Skip active cpus that will be overutilized.
  				 */
  				if ((new_util * hisi_sd_capacity_margin(i)) >
  				    (capacity_orig * SCHED_CAPACITY_SCALE))
  					continue;
  #endif
  				/*
  				 * Limit cpu util to current capacity for
  				 * userspace governor.
  				 */
  				if (new_util > capacity_curr &&
  				    wake_util > (capacity_curr >> 1) &&
  				    cpufreq_userspace_gov_started(i))
  					continue;
  #ifdef CONFIG_SCHED_HISI_VIP
  				/*
  				 * Never push a running normal cfs task to
  				 * a cpu with vip thread.
  				 */
  				if (p->state == TASK_RUNNING &&
  				    !list_empty(&cpu_rq(i)->hisi_vip_thread_list))
  					continue;
  #endif
  #ifdef CONFIG_SCHED_HISI_RUNNING_TASK_ROTATION
  				/*
  				 * When rotation enabled, avoid migrating
  				 * running tasks to active cpus.
  				 */
  				if (p->state == TASK_RUNNING &&
  				    walt_rotation_enabled)
  					continue;
  #endif
  			}
  #endif /* CONFIG_HISI_EAS_SCHED */
  
  			/*
  			 * Pre-compute the maximum possible capacity we expect
  			 * to have available on this CPU once the task is
  			 * enqueued here.
  			 */
  			spare_cap = capacity_orig - new_util;
  
  			if (idle_cpu(i))
  				idle_idx = idle_get_state_idx(cpu_rq(i));
  
  
  			/*
  			 * Case A) Latency sensitive tasks
  			 *
  			 * Unconditionally favoring tasks that prefer idle CPU to
  			 * improve latency.
  			 *
  			 * Looking for:
  			 * - an idle CPU, whatever its idle_state is, since
  			 *   the first CPUs we explore are more likely to be
  			 *   reserved for latency sensitive tasks.
  			 * - a non idle CPU where the task fits in its current
  			 *   capacity and has the maximum spare capacity.
  			 * - a non idle CPU with lower contention from other
  			 *   tasks and running at the lowest possible OPP.
  			 *
  			 * The last two goals tries to favor a non idle CPU
  			 * where the task can run as if it is "almost alone".
  			 * A maximum spare capacity CPU is favoured since
  			 * the task already fits into that CPU's capacity
  			 * without waiting for an OPP chance.
  			 *
  			 * The following code path is the only one in the CPUs
  			 * exploration loop which is always used by
  			 * prefer_idle tasks. It exits the loop with wither a
  			 * best_active_cpu or a target_cpu which should
  			 * represent an optimal choice for latency sensitive
  			 * tasks.
  			 */
  			if (prefer_idle) {
  #ifdef CONFIG_HISI_EAS_SCHED
  				/*
  				 * If favor smaller capacity, we must be !boosted
  				 * and starting at rd->min_cap_orig_cpu.
  				 * Thus, min_cap_orig here will be the min cap_orig
  				 * among all cpus that can reach here.
  				 * Skip all larger capacity cpus.
  				 */
  				if (favor_smaller_capacity) {
  					if (capacity_orig < min_cap_orig)
  						min_cap_orig = capacity_orig;
  					else if (capacity_orig > min_cap_orig)
  						continue;
  				}
  #endif
  				/*
  				 * Case A.1: IDLE CPU
  				 * Return the best IDLE CPU we find:
  				 * - for boosted tasks: the CPU with the highest
  				 * performance (i.e. biggest capacity_orig)
  				 * - for !boosted tasks: the most energy
  				 * efficient CPU (i.e. smallest capacity_orig)
  				 */
  				if (idle_cpu(i)) {
  					if (boosted &&
  					    capacity_orig < target_capacity)
  						continue;
  					if (!boosted &&
  					    capacity_orig > target_capacity)
  						continue;
  					if (capacity_orig == target_capacity &&
  					    sysctl_sched_cstate_aware &&
  					    best_idle_cstate <= idle_idx)
  						continue;
  
  					target_capacity = capacity_orig;
  					best_idle_cstate = idle_idx;
  					best_idle_cpu = i;
  					continue;
  				}
  				if (best_idle_cpu != -1)
  					continue;
  
  				/*
  				 * Case A.2: Target ACTIVE CPU
  				 * Favor CPUs with max spare capacity.
  				 */
  				if (capacity_curr > new_util &&
  				    spare_cap > target_max_spare_cap) {
  					target_max_spare_cap = spare_cap;
  					target_cpu = i;
  					continue;
  				}
  				if (target_cpu != -1)
  					continue;
  
  				/*
  				 * Case A.3: Backup ACTIVE CPU
  				 * Favor CPUs with:
  				 * - lower utilization due to other tasks
  				 * - lower utilization with the task in
  				 */
  				if (wake_util > min_wake_util)
  					continue;
  				if (new_util > best_active_util)
  					continue;
  				min_wake_util = wake_util;
  				best_active_util = new_util;
  				best_active_cpu = i;
  				continue;
  			}
  
  #ifndef CONFIG_SCHED_HISI_USE_WALT
  			/*
  			 * Enforce EAS mode
  			 *
  			 * For non latency sensitive tasks, skip CPUs that
  			 * will be overutilized by moving the task there.
  			 *
  			 * The goal here is to remain in EAS mode as long as
  			 * possible at least for !prefer_idle tasks.
  			 */
  			if ((new_util * hisi_sd_capacity_margin(i)) >
  			    (capacity_orig * SCHED_CAPACITY_SCALE))
  				continue;
  #endif
  #ifdef CONFIG_HISI_EAS_SCHED
  			/*
  			 * Favor CPUs with smaller capacity for non latency
  			 * sensitive tasks.
  			 * However favor larger capacity cpus if boosted.
  			 */
  			if (boosted &&
  			    capacity_orig < target_capacity)
  				continue;
  			if (!boosted &&
  			    capacity_orig > target_capacity)
  				continue;
  #else
  			/*
  			 * Favor CPUs with smaller capacity for non latency
  			 * sensitive tasks.
  			 */
  			if (capacity_orig > target_capacity)
  				continue;
  #endif
  			/*
  			 * Case B) Non latency sensitive tasks on IDLE CPUs.
  			 *
  			 * Find an optimal backup IDLE CPU for non latency
  			 * sensitive tasks.
  			 *
  			 * Looking for:
  			 * - minimizing the capacity_orig,
  			 *   i.e. preferring LITTLE CPUs
  			 * - favoring shallowest idle states
  			 *   i.e. avoid to wakeup deep-idle CPUs
  			 *
  			 * The following code path is used by non latency
  			 * sensitive tasks if IDLE CPUs are available. If at
  			 * least one of such CPUs are available it sets the
  			 * best_idle_cpu to the most suitable idle CPU to be
  			 * selected.
  			 *
  			 * If idle CPUs are available, favour these CPUs to
  			 * improve performances by spreading tasks.
  			 * Indeed, the energy_diff() computed by the caller
  			 * will take care to ensure the minimization of energy
  			 * consumptions without affecting performance.
  			 */
  			if (idle_cpu(i)) {
  				/*
  				 * Skip CPUs in deeper idle state, but only
  				 * if they are also less energy efficient.
  				 * IOW, prefer a deep IDLE LITTLE CPU vs a
  				 * shallow idle big CPU.
  				 */
  				if (capacity_orig == target_capacity &&
  				    sysctl_sched_cstate_aware &&
  				    best_idle_cstate <= idle_idx)
  					continue;
  
  				target_capacity = capacity_orig;
  				best_idle_cstate = idle_idx;
  				best_idle_cpu = i;
  				continue;
  			}
  
  			/*
  			 * Case C) Non latency sensitive tasks on ACTIVE CPUs.
  			 *
  			 * Pack tasks in the most energy efficient capacities.
  			 *
  			 * This task packing strategy prefers more energy
  			 * efficient CPUs (i.e. pack on smaller maximum
  			 * capacity CPUs) while also trying to spread tasks to
  			 * run them all at the lower OPP.
  			 *
  			 * This assumes for example that it's more energy
  			 * efficient to run two tasks on two CPUs at a lower
  			 * OPP than packing both on a single CPU but running
  			 * that CPU at an higher OPP.
  			 *
  			 * Thus, this case keep track of the CPU with the
  			 * smallest maximum capacity and highest spare maximum
  			 * capacity.
  			 */
  
  			/* Favor CPUs with maximum spare capacity */
  			if (capacity_orig == target_capacity &&
  			    spare_cap < target_max_spare_cap)
  				continue;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  			if (capacity_orig == target_capacity &&
  			    (capacity_orig - min_capped_util) ==
  			    target_max_spare_cap &&
  			    new_util > target_util)
  				continue;
  #endif
  
  			target_max_spare_cap = spare_cap;
  			target_capacity = capacity_orig;
  			target_util = new_util;
  			target_cpu = i;
  		}
  
  	} while (sg = sg->next, sg != sd->groups);
  
  	/*
  	 * For non latency sensitive tasks, cases B and C in the previous loop,
  	 * we pick the best IDLE CPU only if we was not able to find a target
  	 * ACTIVE CPU.
  	 *
  	 * Policies priorities:
  	 *
  	 * - prefer_idle tasks:
  	 *
  	 *   a) IDLE CPU available: best_idle_cpu
  	 *   b) ACTIVE CPU where task fits and has the bigger maximum spare
  	 *      capacity (i.e. target_cpu)
  	 *   c) ACTIVE CPU with less contention due to other tasks
  	 *      (i.e. best_active_cpu)
  	 *
  	 * - NON prefer_idle tasks:
  	 *
  	 *   a) ACTIVE CPU: target_cpu
  	 *   b) IDLE CPU: best_idle_cpu
  	 */
  
  	if (prefer_idle && (best_idle_cpu != -1)) {
  		trace_sched_find_best_target(p, prefer_idle, min_util, cpu,
  					     best_idle_cpu, best_active_cpu,
  					     best_idle_cpu);
  
  		return best_idle_cpu;
  	}
  
  	if (target_cpu == -1)
  		target_cpu = prefer_idle
  			? best_active_cpu
  			: best_idle_cpu;
  	else
  		*backup_cpu = prefer_idle
  		? best_active_cpu
  		: best_idle_cpu;
  
  	trace_sched_find_best_target(p, prefer_idle, min_util, cpu,
  				     best_idle_cpu, best_active_cpu,
  				     target_cpu);
  
  	/* it is possible for target and backup
  	 * to select same CPU - if so, drop backup
  	 */
  	if (*backup_cpu == target_cpu)
  		*backup_cpu = -1;
  
  	return target_cpu;
  }
  
  #ifndef CONFIG_HISI_EAS_SCHED
  /*
   * Disable WAKE_AFFINE in the case where task @p doesn't fit in the
   * capacity of either the waking CPU @cpu or the previous CPU @prev_cpu.
   *
   * In that case WAKE_AFFINE doesn't make sense and we'll let
   * BALANCE_WAKE sort things out.
   */
  static int wake_cap(struct task_struct *p, int cpu, int prev_cpu)
  {
  	long min_cap, max_cap;
  
  #ifndef CONFIG_HISI_EAS_SCHED
  	if (!static_branch_unlikely(&sched_asym_cpucapacity))
  		return 0;
  #endif
  
  	min_cap = min(capacity_orig_of(prev_cpu), capacity_orig_of(cpu));
  	max_cap = cpu_rq(cpu)->rd->max_cpu_capacity.val;
  
  	/* Minimum capacity is close to max, no need to abort wake_affine */
  	if (max_cap - min_cap < max_cap >> 3)
  		return 0;
  
  	/* Bring task utilization in sync with prev_cpu */
  #if defined(CONFIG_HISI_EAS_SCHED) && !defined(CONFIG_SCHED_HISI_USE_WALT)
  	if (schedtune_task_boost(p) <= 0 && schedtune_prefer_idle(p) <= 0)
  #endif
  	sync_entity_load_avg(&p->se);
  
  	return !task_fits_capacity(p, min_cap);
  }
  #endif
  
  static bool cpu_overutilized(int cpu)
  {
  	return (capacity_of(cpu) * 1024) < (cpu_util(cpu) * hisi_sd_capacity_margin(cpu));
  }
  
  #ifdef CONFIG_HISI_EAS_SCHED
  
  #ifdef CONFIG_SCHED_HISI_VIP
  static inline void fixup_vip_preempt_type(struct rq *rq)
  {
  	if (rq->vip_preempt_type &&
  	    rq->nr_running <= 1) {
  		rq->vip_preempt_type = NO_VIP_PREEMPT;
  		return;
  	}
  
  	if (!rq->vip_preempt_type &&
  	    rq->highest_hisi_vip_prio &&
  	    rq->nr_running > 1) {
  		rq->vip_preempt_type = VIP_PREEMPT_OTHER;
  		return;
  	}
  }
  #endif
  
  /*
   * This function determines if we should do load balance
   * in ASYM_CPUCAPACITY level sched domain.
   */
  static bool cpu_overutilized_for_lb(int cpu)
  {
  	struct rq *rq = cpu_rq(cpu);
  
  	if (idle_cpu(cpu))
  		return false;
  
  #ifdef CONFIG_SCHED_HISI_VIP
  	fixup_vip_preempt_type(rq);
  	if (rq->vip_preempt_type)
  		return true;
  #endif
  
  	if (capacity_of(cpu) * SCHED_CAPACITY_SCALE <
  	    cpu_util(cpu) * hisi_sd_capacity_margin(cpu))
  		return true;
  
  	/* For misfit task and rtg misfit task. */
  	if (rq->misfit_task_load)
  		return true;
  
  	return false;
  }
  
  static inline bool task_fits(struct task_struct *p, int cpu)
  {
  	unsigned long capacity = capacity_of(cpu);
  	unsigned long util = boosted_task_util(p);
  
  	if (use_pred_load(cpu))
  		util = max(util, task_pred_util(p));
  
  	return (capacity << SCHED_CAPACITY_SHIFT) > (util * hisi_capacity_margin(cpu));
  }
  
  static inline bool task_fits_max(struct task_struct *p, int cpu)
  {
  	unsigned long capacity_orig = capacity_orig_of(cpu);
  	unsigned long max_capacity = cpu_rq(cpu)->rd->max_cpu_capacity.val;
  	cpumask_t allowed_cpus;
  	int allowed_cpu;
  
  	if (capacity_orig == max_capacity)
  		return true;
  
  	if (task_fits(p, cpu))
  		return true;
  
  	/* Now task does not fit. Check if there's a better one. */
  	cpumask_and(&allowed_cpus, &p->cpus_allowed, cpu_online_mask);
  	for_each_cpu(allowed_cpu, &allowed_cpus) {
  		if (capacity_orig_of(allowed_cpu) > capacity_orig)
  			return false; /* Misfit */
  	}
  
  	/* Already largest capacity in allowed cpus. */
  	return true;
  }
  
  static inline bool need_spread_task(struct sched_domain *sd)
  {
  	int cpu;
  
  	for_each_cpu(cpu, sched_domain_span(sd)) {
  		if (!cpu_overutilized(cpu))
  			return false;
  	}
  
  	return true;
  }
  #endif
  
  DEFINE_PER_CPU(struct energy_env, eenv_cache);
  
  /* kernels often have NR_CPUS defined to be much
   * larger than exist in practise on booted systems.
   * Allocate the cpu array for eenv calculations
   * at boot time to avoid massive overprovisioning.
   */
  #ifdef DEBUG_EENV_DECISIONS
  static inline int eenv_debug_size_per_dbg_entry(void)
  {
  	return sizeof(struct _eenv_debug) + (sizeof(unsigned long) * num_possible_cpus());
  }
  
  static inline int eenv_debug_size_per_cpu_entry(void)
  {
  	/* each cpu struct has an array of _eenv_debug structs
  	 * which have an array of unsigned longs at the end -
  	 * the allocation should be extended so that there are
  	 * at least 'num_possible_cpus' entries in the array.
  	 */
  	return EAS_EENV_DEBUG_LEVELS * eenv_debug_size_per_dbg_entry();
  }
  /* given a per-_eenv_cpu debug env ptr, get the ptr for a given index */
  static inline struct _eenv_debug *eenv_debug_entry_ptr(struct _eenv_debug *base, int idx)
  {
  	char *ptr = (char *)base;
  	ptr += (idx * eenv_debug_size_per_dbg_entry());
  	return (struct _eenv_debug *)ptr;
  }
  /* given a pointer to the per-cpu global copy of _eenv_debug, get
   * a pointer to the specified _eenv_cpu debug env.
   */
  static inline struct _eenv_debug *eenv_debug_percpu_debug_env_ptr(struct _eenv_debug *base, int cpu_idx)
  {
  	char *ptr = (char *)base;
  	ptr += (cpu_idx * eenv_debug_size_per_cpu_entry());
  	return (struct _eenv_debug *)ptr;
  }
  
  static inline int eenv_debug_size(void)
  {
  	return num_possible_cpus() * eenv_debug_size_per_cpu_entry();
  }
  #endif
  
  static inline void alloc_eenv(void)
  {
  	int cpu;
  	int cpu_count = num_possible_cpus();
  
  	if (sched_feat(FIND_BEST_TARGET))
  		cpu_count = max(cpu_count, EAS_CPU_BKP + 1);
  
  	for_each_possible_cpu(cpu) {
  		struct energy_env *eenv = &per_cpu(eenv_cache, cpu);
  		eenv->cpu = kmalloc(sizeof(struct eenv_cpu) * cpu_count, GFP_KERNEL);
  		eenv->eenv_cpu_count = cpu_count;
  #ifdef DEBUG_EENV_DECISIONS
  		eenv->debug = (struct _eenv_debug *)kmalloc(eenv_debug_size(), GFP_KERNEL);
  #endif
  	}
  }
  
  static inline void reset_eenv(struct energy_env *eenv)
  {
  	int cpu_count;
  	struct eenv_cpu *cpu;
  #ifdef DEBUG_EENV_DECISIONS
  	struct _eenv_debug *debug;
  	int cpu_idx;
  	debug = eenv->debug;
  #endif
  
  	cpu_count = eenv->eenv_cpu_count;
  	cpu = eenv->cpu;
  	memset(eenv, 0, sizeof(struct energy_env));
  	eenv->cpu = cpu;
  	memset(eenv->cpu, 0, sizeof(struct eenv_cpu)*cpu_count);
  	eenv->eenv_cpu_count = cpu_count;
  
  #ifdef DEBUG_EENV_DECISIONS
  	memset(debug, 0, eenv_debug_size());
  	eenv->debug = debug;
  	for(cpu_idx = 0; cpu_idx < eenv->eenv_cpu_count; cpu_idx++)
  		eenv->cpu[cpu_idx].debug = eenv_debug_percpu_debug_env_ptr(debug, cpu_idx);
  #endif
  }
  /*
   * get_eenv - reset the eenv struct cached for this CPU
   *
   * When the eenv is returned, it is configured to do
   * energy calculations for the maximum number of CPUs
   * the task can be placed on. The prev_cpu entry is
   * filled in here. Callers are responsible for adding
   * other CPU candidates up to eenv->max_cpu_count.
   */
  static inline struct energy_env *get_eenv(struct task_struct *p, int prev_cpu)
  {
  	struct energy_env *eenv;
  	cpumask_t cpumask_possible_cpus;
  	int cpu = smp_processor_id();
  	int i;
  
  	eenv = &(per_cpu(eenv_cache, cpu));
  	reset_eenv(eenv);
  
  	/* populate eenv */
  	eenv->p = p;
  	/* use boosted task util for capacity selection
  	 * during energy calculation, but unboosted task
  	 * util for group utilization calculations
  	 */
  	eenv->util_delta = task_util_est(p);
  	eenv->util_delta_boosted = boosted_task_util(p);
  
  	cpumask_and(&cpumask_possible_cpus, &p->cpus_allowed, cpu_online_mask);
  	eenv->max_cpu_count = cpumask_weight(&cpumask_possible_cpus);
  
  	for (i=0; i < eenv->max_cpu_count; i++)
  		eenv->cpu[i].cpu_id = -1;
  	eenv->cpu[EAS_CPU_PRV].cpu_id = prev_cpu;
  	eenv->next_idx = EAS_CPU_PRV;
  
  	return eenv;
  }
  
  #ifdef CONFIG_HISI_EAS_SCHED
  static inline int wake_to_idle(struct task_struct *p)
  {
  	return p->flags & PF_WAKE_UP_IDLE;
  }
  
  static inline void check_prev_cpu_in_candidates(struct energy_env *eenv)
  {
  	int prev_cpu = eenv->cpu[EAS_CPU_PRV].cpu_id;
  	unsigned long new_util;
  
  	new_util = cpu_util_without(prev_cpu, eenv->p) + task_util_est(eenv->p);
  
  	/* If prev cpu is not a good choice, drop it from energy compare candidates */
  	if ((capacity_of(prev_cpu) * 1024 < new_util * hisi_sd_capacity_margin(prev_cpu)) ||
  	    skip_cpu(prev_cpu)) {
  		int next_cpu = eenv->cpu[EAS_CPU_NXT].cpu_id;
  
  		/* Replace PREV slot with next_cpu */
  		if (next_cpu != -1)
  			eenv->cpu[EAS_CPU_PRV].cpu_id = next_cpu;
  	}
  }
  
  /*
   * Find the smallest cap cpus with spared capacity and pick the
   * max spared capacity one.
   */
  static inline int find_slow_cpu(struct task_struct *p)
  {
  	cpumask_t search_cpus;
  	unsigned long target_cap = ULONG_MAX;
  	unsigned long max_spare_cap = 0;
  	int i;
  	int target_cpu = -1;
  
  	if (p->state != TASK_WAKING)
  		return -1;
  
  	cpumask_and(&search_cpus, &p->cpus_allowed, cpu_online_mask);
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_andnot(&search_cpus, &search_cpus, cpu_isolated_mask);
  #endif
  
  	for_each_cpu(i, &search_cpus) {
  		unsigned long cap_orig, spare_cap;
  
  		cap_orig = capacity_orig_of(i);
  		if (cap_orig > target_cap)
  			continue;
  
  		spare_cap = capacity_spare_without(i, p);
  		if (spare_cap <= max_spare_cap)
  			continue;
  
  		target_cpu = i;
  		target_cap = cap_orig;
  		max_spare_cap = spare_cap;
  	}
  
  	return target_cpu;
  }
  #endif /* CONFIG_HISI_EAS_SCHED */
  
  /*
   * Needs to be called inside rcu_read_lock critical section.
   * sd is a pointer to the sched domain we wish to use for an
   * energy-aware placement option.
   */
  static int find_energy_efficient_cpu(struct sched_domain *sd,
  				     struct task_struct *p,
  				     int cpu, int prev_cpu,
  				     int sync)
  {
  	int use_fbt = sched_feat(FIND_BEST_TARGET);
  	int cpu_iter, eas_cpu_idx = EAS_CPU_NXT;
  	int target_cpu = -1;
  	struct energy_env *eenv;
  
  	if (sysctl_sched_sync_hint_enable && sync) {
  #ifdef CONFIG_HISI_EAS_SCHED
  		if (cpumask_test_cpu(cpu, &p->cpus_allowed) &&
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		    !cpu_isolated(cpu) &&
  #endif
  		    task_fits_max(p, cpu)) {
  			return cpu;
  		}
  #else
  		if (cpumask_test_cpu(cpu, &p->cpus_allowed)) {
  			return cpu;
  		}
  #endif
  	}
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (test_tsk_thread_flag(p, TIF_FAVOR_SMALL_CAP)) {
  		target_cpu = find_slow_cpu(p);
  		if (target_cpu != -1)
  			return target_cpu;
  	}
  #endif
  
  	/* prepopulate energy diff environment */
  	eenv = get_eenv(p, prev_cpu);
  	if (eenv->max_cpu_count < 2)
  		return -1;
  
  	if(!use_fbt) {
  		/*
  		 * using this function outside wakeup balance will not supply
  		 * an sd ptr. Instead, fetch the highest level with energy data.
  		 */
  		if (!sd)
  			sd = rcu_dereference(per_cpu(sd_ea, prev_cpu));
  
  		for_each_cpu_and(cpu_iter, &p->cpus_allowed, sched_domain_span(sd)) {
  			unsigned long spare;
  
  			/* prev_cpu already in list */
  			if (cpu_iter == prev_cpu)
  				continue;
  
  			/*
  			 * Consider only CPUs where the task is expected to
  			 * fit without making the CPU overutilized.
  			 */
  			spare = capacity_spare_without(cpu_iter, p);
  			if (spare * 1024 < capacity_margin * task_util_est(p))
  				continue;
  
  			/* Add CPU candidate */
  			eenv->cpu[eas_cpu_idx++].cpu_id = cpu_iter;
  			eenv->max_cpu_count = eas_cpu_idx;
  
  			/* stop adding CPUs if we have no space left */
  			if (eas_cpu_idx >= eenv->eenv_cpu_count)
  				break;
  		}
  	} else {
  		int boosted = (schedtune_task_boost(p) > 0);
  		int prefer_idle;
  
  		/*
  		 * give compiler a hint that if sched_features
  		 * cannot be changed, it is safe to optimise out
  		 * all if(prefer_idle) blocks.
  		 */
  		prefer_idle = sched_feat(EAS_PREFER_IDLE) ?
  				(schedtune_prefer_idle(p) > 0) : 0;
  #ifdef CONFIG_HISI_EAS_SCHED
  		prefer_idle = prefer_idle || wake_to_idle(p);
  #endif
  
  		eenv->max_cpu_count = EAS_CPU_BKP + 1;
  
  		/* Find a cpu with sufficient capacity */
  		target_cpu = find_best_target(p, &eenv->cpu[EAS_CPU_BKP].cpu_id,
  					      boosted, prefer_idle);
  
  		/* Immediately return a found idle CPU for a prefer_idle task */
  		if (prefer_idle && target_cpu >= 0 && idle_cpu(target_cpu))
  			return target_cpu;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  		/* Skip energy comparison if global boosted */
  		if (global_boost_enable && boosted)
  			return target_cpu;
  #endif
  
  		/* Place target into NEXT slot */
  		eenv->cpu[EAS_CPU_NXT].cpu_id = target_cpu;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  		check_prev_cpu_in_candidates(eenv);
  #endif
  
  		/* take note if no backup was found */
  		if (eenv->cpu[EAS_CPU_BKP].cpu_id < 0)
  			eenv->max_cpu_count = EAS_CPU_BKP;
  
  		/* take note if no target was found */
  		 if (eenv->cpu[EAS_CPU_NXT].cpu_id < 0)
  			 eenv->max_cpu_count = EAS_CPU_NXT;
  	}
  
  	if (eenv->max_cpu_count == EAS_CPU_NXT) {
  		/*
  		 * we did not find any energy-awareness
  		 * candidates beyond prev_cpu, so we will
  		 * fall-back to the regular slow-path.
  		 */
  		return -1;
  	}
  
  	/* find most energy-efficient CPU */
  	target_cpu = select_energy_cpu_idx(eenv) < 0 ? -1 :
  					eenv->cpu[eenv->next_idx].cpu_id;
  
  	return target_cpu;
  }
  
  static inline bool nohz_kick_needed(struct rq *rq, bool only_update);
  static void nohz_balancer_kick(bool only_update);
  
  /*
   * wake_energy: Make the decision if we want to use an energy-aware
   * wakeup task placement or not. This is limited to situations where
   * we cannot use energy-awareness right now.
   *
   * Returns TRUE if we should attempt energy-aware wakeup, FALSE if not.
   *
   * Should only be called from select_task_rq_fair inside the RCU
   * read-side critical section.
   */
  static inline int wake_energy(struct task_struct *p, int prev_cpu,
  			      int sd_flag, int wake_flags)
  {
  	struct sched_domain *sd = NULL;
  	int sync = wake_flags & WF_SYNC;
  
  	sd = rcu_dereference_sched(cpu_rq(prev_cpu)->sd);
  
  	/*
  	 * Check all definite no-energy-awareness conditions
  	 */
  	if (!sd)
  		return false;
  
  	if (!energy_aware())
  		return false;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (need_spread_task(sd))
  #else
  	if (sd_overutilized(sd))
  #endif
  		return false;
  
  	/*
  	 * we cannot do energy-aware wakeup placement sensibly
  	 * for tasks with 0 utilization, so let them be placed
  	 * according to the normal strategy.
  	 * However if fbt is in use we may still benefit from
  	 * the heuristics we use there in selecting candidate
  	 * CPUs.
  	 */
  	if (unlikely(!sched_feat(FIND_BEST_TARGET) && !task_util_est(p)))
  		return false;
  
  	if(!sched_feat(EAS_PREFER_IDLE)){
  		/*
  		 * Force prefer-idle tasks into the slow path, this may not happen
  		 * if none of the sd flags matched.
  		 */
  		if (schedtune_prefer_idle(p) > 0 && !sync)
  			return false;
  	}
  	return true;
  }
  
  /*
   * select_task_rq_fair: Select target runqueue for the waking task in domains
   * that have the 'sd_flag' flag set. In practice, this is SD_BALANCE_WAKE,
   * SD_BALANCE_FORK, or SD_BALANCE_EXEC.
   *
   * Balances load by selecting the idlest cpu in the idlest group, or under
   * certain conditions an idle sibling cpu if the domain has SD_WAKE_AFFINE set.
   *
   * Returns the target cpu number.
   *
   * preempt must be disabled.
   */
  static int
  select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_flags,
  		    int sibling_count_hint)
  {
  	struct sched_domain *tmp, *affine_sd = NULL;
  	struct sched_domain *sd = NULL, *energy_sd = NULL;
  	int cpu = smp_processor_id();
  	int new_cpu = prev_cpu;
  	int want_affine = 0;
  	int want_energy = 0;
  	int sync = wake_flags & WF_SYNC;
  #ifdef CONFIG_HISI_RTG
  	struct related_thread_group *grp = NULL;
  	int rtg_cpu = -1;
  #endif
  
  #ifdef CONFIG_SCHED_HISI_VIP
  	if (p->hisi_vip_prio) {
  		int vip_cpu = find_vip_cpu(p);
  
  		if (vip_cpu != -1)
  			return vip_cpu;
  		else
  			return prev_cpu;
  	}
  #endif
  
  	rcu_read_lock();
  #ifdef CONFIG_HISI_RTG
  	grp = task_related_thread_group(p);
  	if (grp) {
  		struct sched_cluster *prefer_cluster = grp->preferred_cluster;
  
  		if (prefer_cluster) {
  			/*
  			 * We're going to need the task's util for cpu_util_wake
  			 * in find_rtg_cpu. Sync it up to prev_cpu's
  			 * last_update_time.
  			 */
  			sync_entity_load_avg(&p->se);
  			rtg_cpu = find_rtg_cpu(p, &prefer_cluster->cpus);
  			if (rtg_cpu != -1){
  				rcu_read_unlock();
  				return rtg_cpu;
  			}
  		}
  	}
  #endif
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	want_energy = wake_energy(p, prev_cpu, sd_flag, wake_flags);
  #endif
  	if (sd_flag & SD_BALANCE_WAKE) {
  		record_wakee(p);
  #ifndef CONFIG_HISI_EAS_SCHED
  		want_energy = wake_energy(p, prev_cpu, sd_flag, wake_flags);
  		want_affine = !want_energy &&
  			      !wake_wide(p, sibling_count_hint) &&
  			      !wake_cap(p, cpu, prev_cpu) &&
  			      cpumask_test_cpu(cpu, &p->cpus_allowed);
  #endif
  	}
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (boot_boost) {
  		int boost_cpu = find_global_boost_cpu(p);
  		if (boost_cpu != -1){
  			rcu_read_unlock();
  			return boost_cpu;
  		}
  	}
  #endif
  
  	for_each_domain(cpu, tmp) {
  		if (!(tmp->flags & SD_LOAD_BALANCE))
  			continue;
  
  		/*
  		 * If both cpu and prev_cpu are part of this domain,
  		 * cpu is a valid SD_WAKE_AFFINE target.
  		 */
  		if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
  		    cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
  			affine_sd = tmp;
  			break;
  		}
  
  		/*
  		 * If we are able to try an energy-aware wakeup,
  		 * select the highest non-overutilized sched domain
  		 * which includes this cpu and prev_cpu
  		 *
  		 * maybe want to not test prev_cpu and only consider
  		 * the current one?
  		 */
  		if (want_energy &&
  		    !sd_overutilized(tmp) &&
  		    cpumask_test_cpu(prev_cpu, sched_domain_span(tmp)))
  			energy_sd = tmp;
  
  		if (tmp->flags & sd_flag)
  			sd = tmp;
  		else if (!(want_affine || want_energy))
  			break;
  	}
  
  	if (affine_sd) {
  		sd = NULL; /* Prefer wake_affine over balance flags */
  		if (cpu == prev_cpu)
  			goto pick_cpu;
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		if (wake_affine(affine_sd, p, prev_cpu, sync) &&
  		    !cpu_isolated(cpu))
  #else
  		if (wake_affine(affine_sd, p, prev_cpu, sync))
  #endif
  			new_cpu = cpu;
  	}
  
  	if (sd && !(sd_flag & SD_BALANCE_FORK)) {
  		/*
  		 * We're going to need the task's util for capacity_spare_without
  		 * in find_idlest_group. Sync it up to prev_cpu's
  		 * last_update_time.
  		 */
  #if defined(CONFIG_HISI_EAS_SCHED) && !defined(CONFIG_SCHED_HISI_USE_WALT)
  		if (schedtune_task_boost(p) <= 0 && schedtune_prefer_idle(p) <= 0)
  #endif
  		sync_entity_load_avg(&p->se);
  	}
  
  	if (!sd) {
  pick_cpu:
  		if (sd_flag & SD_BALANCE_WAKE) /* XXX always ? */
  			new_cpu = select_idle_sibling(p, prev_cpu, new_cpu);
  
  	} else {
  #ifdef CONFIG_HISI_EAS_SCHED
  		if (want_energy)
  #else
  		if (energy_sd)
  #endif
  			new_cpu = find_energy_efficient_cpu(energy_sd, p, cpu, prev_cpu, sync);
  
  		/* if we did an energy-aware placement and had no choices available
  		 * then fall back to the default find_idlest_cpu choice
  		 */
  #ifdef CONFIG_HISI_EAS_SCHED
  		if (!want_energy || (want_energy && new_cpu == -1))
  #else
  		if (!energy_sd || (energy_sd && new_cpu == -1))
  #endif
  			new_cpu = find_idlest_cpu(sd, p, cpu, prev_cpu, sd_flag);
  	}
  
  	rcu_read_unlock();
  
  #ifdef CONFIG_NO_HZ_COMMON
  	if (nohz_kick_needed(cpu_rq(new_cpu), true))
  		nohz_balancer_kick(true);
  #endif
  
  	return new_cpu;
  }
  
  /*
   * Called immediately before a task is migrated to a new cpu; task_cpu(p) and
   * cfs_rq_of(p) references at time of call are still valid and identify the
   * previous cpu. The caller guarantees p->pi_lock or task_rq(p)->lock is held.
   */
  static void migrate_task_rq_fair(struct task_struct *p)
  {
  	/*
  	 * As blocked tasks retain absolute vruntime the migration needs to
  	 * deal with this by subtracting the old and adding the new
  	 * min_vruntime -- the latter is done by enqueue_entity() when placing
  	 * the task on the new runqueue.
  	 */
  	if (p->state == TASK_WAKING) {
  		struct sched_entity *se = &p->se;
  		struct cfs_rq *cfs_rq = cfs_rq_of(se);
  		u64 min_vruntime;
  
  #ifndef CONFIG_64BIT
  		u64 min_vruntime_copy;
  
  		do {
  			min_vruntime_copy = cfs_rq->min_vruntime_copy;
  			smp_rmb();
  			min_vruntime = cfs_rq->min_vruntime;
  		} while (min_vruntime != min_vruntime_copy);
  #else
  		min_vruntime = cfs_rq->min_vruntime;
  #endif
  
  		se->vruntime -= min_vruntime;
  	}
  
  	/*
  	 * We are supposed to update the task to "current" time, then its up to date
  	 * and ready to go to new CPU/cfs_rq. But we have difficulty in getting
  	 * what current time is, so simply throw away the out-of-date time. This
  	 * will result in the wakee task is less decayed, but giving the wakee more
  	 * load sounds not bad.
  	 */
  	remove_entity_load_avg(&p->se);
  
  	/* Tell new CPU we are migrated */
  	p->se.avg.last_update_time = 0;
  
  	/* We have migrated, no longer consider this task hot */
  	p->se.exec_start = 0;
  }
  
  static void task_dead_fair(struct task_struct *p)
  {
  	remove_entity_load_avg(&p->se);
  }
  #endif /* CONFIG_SMP */
  
  #ifdef CONFIG_HISI_CORE_CTRL
  static void inc_cfs_nr_heavy_running(struct rq *update_rq,
  				     struct task_struct *p)
  {
  	if (p->heavy_task)
  		return;
  
  	if (!task_fits_max(p, cpu_of(update_rq))) {
  		update_rq->nr_heavy_running++;
  		p->heavy_task = true;
  	}
  }
  
  static void dec_cfs_nr_heavy_running(struct rq *update_rq,
  				     struct task_struct *p)
  {
  	if (p->heavy_task) {
  		update_rq->nr_heavy_running--;
  		p->heavy_task = false;
  	}
  
  	WARN_ON(update_rq->nr_heavy_running < 0);
  }
  
  static void update_cfs_nr_heavy_running(struct rq *update_rq,
  					struct task_struct *p)
  {
  	bool is_heavy = update_rq->misfit_task_load > 0;
  
  	if (is_heavy != p->heavy_task) {
  		core_ctl_update_nr_prod(update_rq);
  
  		p->heavy_task = is_heavy;
  
  		if (is_heavy) {
  			update_rq->nr_heavy_running++;
  		} else {
  			update_rq->nr_heavy_running--;
  			WARN_ON(update_rq->nr_heavy_running < 0);
  		}
  	}
  }
  #endif
  
  static unsigned long
  wakeup_gran(struct sched_entity *curr, struct sched_entity *se)
  {
  	unsigned long gran = sysctl_sched_wakeup_granularity;
  
  	/*
  	 * Since its curr running now, convert the gran from real-time
  	 * to virtual-time in his units.
  	 *
  	 * By using 'se' instead of 'curr' we penalize light tasks, so
  	 * they get preempted easier. That is, if 'se' < 'curr' then
  	 * the resulting gran will be larger, therefore penalizing the
  	 * lighter, if otoh 'se' > 'curr' then the resulting gran will
  	 * be smaller, again penalizing the lighter task.
  	 *
  	 * This is especially important for buddies when the leftmost
  	 * task is higher priority than the buddy.
  	 */
  	return calc_delta_fair(gran, se);
  }
  
  /*
   * Should 'se' preempt 'curr'.
   *
   *             |s1
   *        |s2
   *   |s3
   *         g
   *      |<--->|c
   *
   *  w(c, s1) = -1
   *  w(c, s2) =  0
   *  w(c, s3) =  1
   *
   */
  static int
  wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
  {
  	s64 gran, vdiff = curr->vruntime - se->vruntime;
  
  	if (vdiff <= 0)
  		return -1;
  
  	gran = wakeup_gran(curr, se);
  	if (vdiff > gran)
  		return 1;
  
  	return 0;
  }
  
  static void set_last_buddy(struct sched_entity *se)
  {
  	if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
  		return;
  
  	for_each_sched_entity(se) {
  		if (SCHED_WARN_ON(!se->on_rq))
  			return;
  		cfs_rq_of(se)->last = se;
  	}
  }
  
  static void set_next_buddy(struct sched_entity *se)
  {
  	if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
  		return;
  
  	for_each_sched_entity(se) {
  		if (SCHED_WARN_ON(!se->on_rq))
  			return;
  		cfs_rq_of(se)->next = se;
  	}
  }
  
  static void set_skip_buddy(struct sched_entity *se)
  {
  	for_each_sched_entity(se)
  		cfs_rq_of(se)->skip = se;
  }
  
  /*
   * Preempt the current task with a newly woken task if needed:
   */
  static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
  {
  	struct task_struct *curr = rq->curr;
  	struct sched_entity *se = &curr->se, *pse = &p->se;
  	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
  	int scale = cfs_rq->nr_running >= sched_nr_latency;
  	int next_buddy_marked = 0;
  
  	if (unlikely(se == pse))
  		return;
  
  	/*
  	 * This is possible from callers such as attach_tasks(), in which we
  	 * unconditionally check_prempt_curr() after an enqueue (which may have
  	 * lead to a throttle).  This both saves work and prevents false
  	 * next-buddy nomination below.
  	 */
  	if (unlikely(throttled_hierarchy(cfs_rq_of(pse))))
  		return;
  
  	if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK)) {
  		set_next_buddy(pse);
  		next_buddy_marked = 1;
  	}
  
  	/*
  	 * We can come here with TIF_NEED_RESCHED already set from new task
  	 * wake up path.
  	 *
  	 * Note: this also catches the edge-case of curr being in a throttled
  	 * group (e.g. via set_curr_task), since update_curr() (in the
  	 * enqueue of curr) will have resulted in resched being set.  This
  	 * prevents us from potentially nominating it as a false LAST_BUDDY
  	 * below.
  	 */
  	if (test_tsk_need_resched(curr))
  		return;
  
  	/* Idle tasks are by definition preempted by non-idle tasks. */
  	if (unlikely(curr->policy == SCHED_IDLE) &&
  	    likely(p->policy != SCHED_IDLE))
  		goto preempt;
  
  	/*
  	 * Batch and idle tasks do not preempt non-idle tasks (their preemption
  	 * is driven by the tick):
  	 */
  	if (unlikely(p->policy != SCHED_NORMAL) || !sched_feat(WAKEUP_PREEMPTION))
  		return;
  
  	find_matching_se(&se, &pse);
  	update_curr(cfs_rq_of(se));
  	BUG_ON(!pse);
  #ifdef CONFIG_HW_VIP_THREAD
  	if (p->static_vip || atomic64_read(&p->dynamic_vip)) {
  		trace_sched_vip_sched(p, "vip_preempt");
  		goto preempt;
  	}
  #endif
  #ifdef CONFIG_SCHED_HISI_VIP
  	if (p->hisi_vip_prio)
  		goto preempt;
  #endif
  
  	if (wakeup_preempt_entity(se, pse) == 1) {
  		/*
  		 * Bias pick_next to pick the sched entity that is
  		 * triggering this preemption.
  		 */
  		if (!next_buddy_marked)
  			set_next_buddy(pse);
  		goto preempt;
  	}
  
  	return;
  
  preempt:
  	resched_curr(rq);
  	/*
  	 * Only set the backward buddy when the current task is still
  	 * on the rq. This can happen when a wakeup gets interleaved
  	 * with schedule on the ->pre_schedule() or idle_balance()
  	 * point, either of which can * drop the rq lock.
  	 *
  	 * Also, during early boot the idle thread is in the fair class,
  	 * for obvious reasons its a bad idea to schedule back to it.
  	 */
  	if (unlikely(!se->on_rq || curr == rq->idle))
  		return;
  
  	if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
  		set_last_buddy(se);
  }
  
  static struct task_struct *
  pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
  {
  	struct cfs_rq *cfs_rq = &rq->cfs;
  	struct sched_entity *se;
  	struct task_struct *p;
  	int new_tasks;
  
  again:
  	if (!cfs_rq->nr_running)
  		goto idle;
  
  #ifdef CONFIG_SCHED_HISI_VIP
  	p = pick_next_hisi_vip_thread(rq);
  
  	if (p) {
  		put_prev_task(rq, prev);
  
  		do {
  			se = pick_next_entity(cfs_rq, NULL);
  			cfs_rq = group_cfs_rq(se);
  		} while (cfs_rq);
  
  		/*
  		 * If the CFS picked task is a per-cpu task, pick it
  		 * to prevent starving.
  		 * Otherwise go with our vip task.
  		 */
  		if (task_of(se)->nr_cpus_allowed == 1)
  			p = task_of(se);
  
  		se = &p->se;
  		for_each_sched_entity(se)
  			set_next_entity(cfs_rq_of(se), se);
  
  		goto done;
  	}
  #endif
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  	if (prev->sched_class != &fair_sched_class)
  		goto simple;
  
  	/*
  	 * Because of the set_next_buddy() in dequeue_task_fair() it is rather
  	 * likely that a next task is from the same cgroup as the current.
  	 *
  	 * Therefore attempt to avoid putting and setting the entire cgroup
  	 * hierarchy, only change the part that actually changes.
  	 */
  
  	do {
  		struct sched_entity *curr = cfs_rq->curr;
  
  		/*
  		 * Since we got here without doing put_prev_entity() we also
  		 * have to consider cfs_rq->curr. If it is still a runnable
  		 * entity, update_curr() will update its vruntime, otherwise
  		 * forget we've ever seen it.
  		 */
  		if (curr) {
  			if (curr->on_rq)
  				update_curr(cfs_rq);
  			else
  				curr = NULL;
  
  			/*
  			 * This call to check_cfs_rq_runtime() will do the
  			 * throttle and dequeue its entity in the parent(s).
  			 * Therefore the nr_running test will indeed
  			 * be correct.
  			 */
  			if (unlikely(check_cfs_rq_runtime(cfs_rq))) {
  				cfs_rq = &rq->cfs;
  
  				if (!cfs_rq->nr_running)
  					goto idle;
  
  				goto simple;
  			}
  		}
  
  		se = pick_next_entity(cfs_rq, curr);
  		cfs_rq = group_cfs_rq(se);
  	} while (cfs_rq);
  
  	p = task_of(se);
  #ifdef CONFIG_HW_VIP_THREAD
  	/*
  	 * pick vip or temp vip thread
  	 */
  	 pick_vip_thread(rq, &p, &se);
  #endif
  
  	/*
  	 * Since we haven't yet done put_prev_entity and if the selected task
  	 * is a different task than we started out with, try and touch the
  	 * least amount of cfs_rqs.
  	 */
  	if (prev != p) {
  		struct sched_entity *pse = &prev->se;
  
  		while (!(cfs_rq = is_same_group(se, pse))) {
  			int se_depth = se->depth;
  			int pse_depth = pse->depth;
  
  			if (se_depth <= pse_depth) {
  				put_prev_entity(cfs_rq_of(pse), pse);
  				pse = parent_entity(pse);
  			}
  			if (se_depth >= pse_depth) {
  				set_next_entity(cfs_rq_of(se), se);
  				se = parent_entity(se);
  			}
  		}
  
  		put_prev_entity(cfs_rq, pse);
  		set_next_entity(cfs_rq, se);
  	}
  
  	if (hrtick_enabled(rq))
  		hrtick_start_fair(rq, p);
  
  	update_misfit_status(p, rq);
  
  	return p;
  simple:
  #endif
  
  	put_prev_task(rq, prev);
  
  	do {
  		se = pick_next_entity(cfs_rq, NULL);
  		set_next_entity(cfs_rq, se);
  		cfs_rq = group_cfs_rq(se);
  	} while (cfs_rq);
  
  	p = task_of(se);
  
  #ifdef CONFIG_SCHED_HISI_VIP
  done:
  #endif
  	if (hrtick_enabled(rq))
  		hrtick_start_fair(rq, p);
  
  	update_misfit_status(p, rq);
  
  	return p;
  
  idle:
  	update_misfit_status(NULL, rq);
  	new_tasks = idle_balance(rq, rf);
  
  	/*
  	 * Because idle_balance() releases (and re-acquires) rq->lock, it is
  	 * possible for any higher priority task to appear. In that case we
  	 * must re-start the pick_next_entity() loop.
  	 */
  	if (new_tasks < 0)
  		return RETRY_TASK;
  
  	if (new_tasks > 0)
  		goto again;
  
  	return NULL;
  }
  
  /*
   * Account for a descheduled task:
   */
  static void put_prev_task_fair(struct rq *rq, struct task_struct *prev)
  {
  	struct sched_entity *se = &prev->se;
  	struct cfs_rq *cfs_rq;
  
  	for_each_sched_entity(se) {
  		cfs_rq = cfs_rq_of(se);
  		put_prev_entity(cfs_rq, se);
  	}
  }
  
  /*
   * sched_yield() is very simple
   *
   * The magic of dealing with the ->skip buddy is in pick_next_entity.
   */
  static void yield_task_fair(struct rq *rq)
  {
  	struct task_struct *curr = rq->curr;
  	struct cfs_rq *cfs_rq = task_cfs_rq(curr);
  	struct sched_entity *se = &curr->se;
  
  	/*
  	 * Are we the only task in the tree?
  	 */
  	if (unlikely(rq->nr_running == 1))
  		return;
  
  	clear_buddies(cfs_rq, se);
  
  	if (curr->policy != SCHED_BATCH) {
  		update_rq_clock(rq);
  		/*
  		 * Update run-time statistics of the 'current'.
  		 */
  		update_curr(cfs_rq);
  		/*
  		 * Tell update_rq_clock() that we've just updated,
  		 * so we don't do microscopic update in schedule()
  		 * and double the fastpath cost.
  		 */
  		rq_clock_skip_update(rq, true);
  	}
  
  	set_skip_buddy(se);
  }
  
  static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preempt)
  {
  	struct sched_entity *se = &p->se;
  
  	/* throttled hierarchies are not runnable */
  	if (!se->on_rq || throttled_hierarchy(cfs_rq_of(se)))
  		return false;
  
  	/* Tell the scheduler that we'd really like pse to run next. */
  	set_next_buddy(se);
  
  	yield_task_fair(rq);
  
  	return true;
  }
  
  #ifdef CONFIG_SMP
  /**************************************************
   * Fair scheduling class load-balancing methods.
   *
   * BASICS
   *
   * The purpose of load-balancing is to achieve the same basic fairness the
   * per-cpu scheduler provides, namely provide a proportional amount of compute
   * time to each task. This is expressed in the following equation:
   *
   *   W_i,n/P_i == W_j,n/P_j for all i,j                               (1)
   *
   * Where W_i,n is the n-th weight average for cpu i. The instantaneous weight
   * W_i,0 is defined as:
   *
   *   W_i,0 = \Sum_j w_i,j                                             (2)
   *
   * Where w_i,j is the weight of the j-th runnable task on cpu i. This weight
   * is derived from the nice value as per sched_prio_to_weight[].
   *
   * The weight average is an exponential decay average of the instantaneous
   * weight:
   *
   *   W'_i,n = (2^n - 1) / 2^n * W_i,n + 1 / 2^n * W_i,0               (3)
   *
   * C_i is the compute capacity of cpu i, typically it is the
   * fraction of 'recent' time available for SCHED_OTHER task execution. But it
   * can also include other factors [XXX].
   *
   * To achieve this balance we define a measure of imbalance which follows
   * directly from (1):
   *
   *   imb_i,j = max{ avg(W/C), W_i/C_i } - min{ avg(W/C), W_j/C_j }    (4)
   *
   * We them move tasks around to minimize the imbalance. In the continuous
   * function space it is obvious this converges, in the discrete case we get
   * a few fun cases generally called infeasible weight scenarios.
   *
   * [XXX expand on:
   *     - infeasible weights;
   *     - local vs global optima in the discrete case. ]
   *
   *
   * SCHED DOMAINS
   *
   * In order to solve the imbalance equation (4), and avoid the obvious O(n^2)
   * for all i,j solution, we create a tree of cpus that follows the hardware
   * topology where each level pairs two lower groups (or better). This results
   * in O(log n) layers. Furthermore we reduce the number of cpus going up the
   * tree to only the first of the previous level and we decrease the frequency
   * of load-balance at each level inv. proportional to the number of cpus in
   * the groups.
   *
   * This yields:
   *
   *     log_2 n     1     n
   *   \Sum       { --- * --- * 2^i } = O(n)                            (5)
   *     i = 0      2^i   2^i
   *                               `- size of each group
   *         |         |     `- number of cpus doing load-balance
   *         |         `- freq
   *         `- sum over all levels
   *
   * Coupled with a limit on how many tasks we can migrate every balance pass,
   * this makes (5) the runtime complexity of the balancer.
   *
   * An important property here is that each CPU is still (indirectly) connected
   * to every other cpu in at most O(log n) steps:
   *
   * The adjacency matrix of the resulting graph is given by:
   *
   *             log_2 n
   *   A_i,j = \Union     (i % 2^k == 0) && i / 2^(k+1) == j / 2^(k+1)  (6)
   *             k = 0
   *
   * And you'll find that:
   *
   *   A^(log_2 n)_i,j != 0  for all i,j                                (7)
   *
   * Showing there's indeed a path between every cpu in at most O(log n) steps.
   * The task movement gives a factor of O(m), giving a convergence complexity
   * of:
   *
   *   O(nm log n),  n := nr_cpus, m := nr_tasks                        (8)
   *
   *
   * WORK CONSERVING
   *
   * In order to avoid CPUs going idle while there's still work to do, new idle
   * balancing is more aggressive and has the newly idle cpu iterate up the domain
   * tree itself instead of relying on other CPUs to bring it work.
   *
   * This adds some complexity to both (5) and (8) but it reduces the total idle
   * time.
   *
   * [XXX more?]
   *
   *
   * CGROUPS
   *
   * Cgroups make a horror show out of (2), instead of a simple sum we get:
   *
   *                                s_k,i
   *   W_i,0 = \Sum_j \Prod_k w_k * -----                               (9)
   *                                 S_k
   *
   * Where
   *
   *   s_k,i = \Sum_j w_i,j,k  and  S_k = \Sum_i s_k,i                 (10)
   *
   * w_i,j,k is the weight of the j-th runnable task in the k-th cgroup on cpu i.
   *
   * The big problem is S_k, its a global sum needed to compute a local (W_i)
   * property.
   *
   * [XXX write more on how we solve this.. _after_ merging pjt's patches that
   *      rewrite all of this once again.]
   */
  
  static unsigned long __read_mostly max_load_balance_interval = HZ/10;
  
  enum fbq_type { regular, remote, all };
  
  enum group_type {
  	group_other = 0,
  #ifdef CONFIG_SCHED_HISI_VIP
  	group_vip_preempt,
  #endif
  	group_misfit_task,
  	group_imbalanced,
  	group_overloaded,
  };
  
  #define LBF_ALL_PINNED	0x01
  #define LBF_NEED_BREAK	0x02
  #define LBF_DST_PINNED  0x04
  #define LBF_SOME_PINNED	0x08
  
  struct lb_env {
  	struct sched_domain	*sd;
  
  	struct rq		*src_rq;
  	int			src_cpu;
  
  	int			dst_cpu;
  	struct rq		*dst_rq;
  
  	struct cpumask		*dst_grpmask;
  	int			new_dst_cpu;
  	enum cpu_idle_type	idle;
  	long			imbalance;
  	unsigned int		src_grp_nr_running;
  	/* The set of CPUs under consideration for load-balancing */
  	struct cpumask		*cpus;
  
  	unsigned int		flags;
  
  	unsigned int		loop;
  	unsigned int		loop_break;
  	unsigned int		loop_max;
  
  	enum fbq_type		fbq_type;
  	enum group_type		src_grp_type;
  	struct list_head	tasks;
  };
  
  /*
   * Is this task likely cache-hot:
   */
  static int task_hot(struct task_struct *p, struct lb_env *env)
  {
  	s64 delta;
  
  	lockdep_assert_held(&env->src_rq->lock);
  
  	if (p->sched_class != &fair_sched_class)
  		return 0;
  
  	if (unlikely(p->policy == SCHED_IDLE))
  		return 0;
  
  	/*
  	 * Buddy candidates are cache hot:
  	 */
  	if (sched_feat(CACHE_HOT_BUDDY) && env->dst_rq->nr_running &&
  			(&p->se == cfs_rq_of(&p->se)->next ||
  			 &p->se == cfs_rq_of(&p->se)->last))
  		return 1;
  
  	if (sysctl_sched_migration_cost == -1)
  		return 1;
  	if (sysctl_sched_migration_cost == 0)
  		return 0;
  
  	delta = rq_clock_task(env->src_rq) - p->se.exec_start;
  
  	return delta < (s64)sysctl_sched_migration_cost;
  }
  
  #ifdef CONFIG_NUMA_BALANCING
  /*
   * Returns 1, if task migration degrades locality
   * Returns 0, if task migration improves locality i.e migration preferred.
   * Returns -1, if task migration is not affected by locality.
   */
  static int migrate_degrades_locality(struct task_struct *p, struct lb_env *env)
  {
  	struct numa_group *numa_group = rcu_dereference(p->numa_group);
  	unsigned long src_faults, dst_faults;
  	int src_nid, dst_nid;
  
  	if (!static_branch_likely(&sched_numa_balancing))
  		return -1;
  
  	if (!p->numa_faults || !(env->sd->flags & SD_NUMA))
  		return -1;
  
  	src_nid = cpu_to_node(env->src_cpu);
  	dst_nid = cpu_to_node(env->dst_cpu);
  
  	if (src_nid == dst_nid)
  		return -1;
  
  	/* Migrating away from the preferred node is always bad. */
  	if (src_nid == p->numa_preferred_nid) {
  		if (env->src_rq->nr_running > env->src_rq->nr_preferred_running)
  			return 1;
  		else
  			return -1;
  	}
  
  	/* Encourage migration to the preferred node. */
  	if (dst_nid == p->numa_preferred_nid)
  		return 0;
  
  	/* Leaving a core idle is often worse than degrading locality. */
  	if (env->idle != CPU_NOT_IDLE)
  		return -1;
  
  	if (numa_group) {
  		src_faults = group_faults(p, src_nid);
  		dst_faults = group_faults(p, dst_nid);
  	} else {
  		src_faults = task_faults(p, src_nid);
  		dst_faults = task_faults(p, dst_nid);
  	}
  
  	return dst_faults < src_faults;
  }
  
  #else
  static inline int migrate_degrades_locality(struct task_struct *p,
  					     struct lb_env *env)
  {
  	return -1;
  }
  #endif
  
  /*
   * can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
   */
  static
  int can_migrate_task(struct task_struct *p, struct lb_env *env)
  {
  	int tsk_cache_hot;
  
  	lockdep_assert_held(&env->src_rq->lock);
  
  	/*
  	 * We do not migrate tasks that are:
  	 * 1) throttled_lb_pair, or
  	 * 2) cannot be migrated to this CPU due to cpus_allowed, or
  	 * 3) running (obviously), or
  	 * 4) are cache-hot on their current CPU.
  	 */
  	if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
  		return 0;
  
  	if (!cpumask_test_cpu(env->dst_cpu, &p->cpus_allowed)) {
  		int cpu;
  
  		schedstat_inc(p->se.statistics.nr_failed_migrations_affine);
  
  		env->flags |= LBF_SOME_PINNED;
  
  		/*
  		 * Remember if this task can be migrated to any other cpu in
  		 * our sched_group. We may want to revisit it if we couldn't
  		 * meet load balance goals by pulling other tasks on src_cpu.
  		 *
  		 * Avoid computing new_dst_cpu for NEWLY_IDLE or if we have
  		 * already computed one in current iteration.
  		 */
  		if (env->idle == CPU_NEWLY_IDLE || (env->flags & LBF_DST_PINNED))
  			return 0;
  
  		/* Prevent to re-select dst_cpu via env's cpus */
  		for_each_cpu_and(cpu, env->dst_grpmask, env->cpus) {
  			if (cpumask_test_cpu(cpu, &p->cpus_allowed)) {
  				env->flags |= LBF_DST_PINNED;
  				env->new_dst_cpu = cpu;
  				break;
  			}
  		}
  
  		return 0;
  	}
  
  	/* Record that we found atleast one task that could run on dst_cpu */
  	env->flags &= ~LBF_ALL_PINNED;
  
  	if (task_running(env->src_rq, p)) {
  		schedstat_inc(p->se.statistics.nr_failed_migrations_running);
  		return 0;
  	}
  
  	/*
  	 * Aggressive migration if:
  	 * 1) destination numa is preferred
  	 * 2) task is cache cold, or
  	 * 3) too many balance attempts have failed.
  	 */
  	tsk_cache_hot = migrate_degrades_locality(p, env);
  	if (tsk_cache_hot == -1)
  		tsk_cache_hot = task_hot(p, env);
  
  	if (tsk_cache_hot <= 0 ||
  	    env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
  		if (tsk_cache_hot == 1) {
  			schedstat_inc(env->sd->lb_hot_gained[env->idle]);
  			schedstat_inc(p->se.statistics.nr_forced_migrations);
  		}
  		return 1;
  	}
  
  	schedstat_inc(p->se.statistics.nr_failed_migrations_hot);
  	return 0;
  }
  
  /*
   * detach_task() -- detach the task for the migration specified in env
   */
  static void detach_task(struct task_struct *p, struct lb_env *env,
  			struct rq_flags *rf)
  {
  	lockdep_assert_held(&env->src_rq->lock);
  
  	p->on_rq = TASK_ON_RQ_MIGRATING;
  	deactivate_task(env->src_rq, p, DEQUEUE_NOCLOCK);
  	rq_unpin_lock(env->src_rq, rf);
  #ifdef CONFIG_SCHED_WALT
  	double_lock_balance(env->src_rq, env->dst_rq);
  #endif
  	set_task_cpu(p, env->dst_cpu);
  #ifdef CONFIG_SCHED_WALT
  	double_unlock_balance(env->src_rq, env->dst_rq);
  #endif
  	rq_repin_lock(env->src_rq, rf);
  }
  
  /*
   * detach_one_task() -- tries to dequeue exactly one task from env->src_rq, as
   * part of active balancing operations within "domain".
   *
   * Returns a task if successful and NULL otherwise.
   */
  static struct task_struct *detach_one_task(struct lb_env *env,
  					   struct rq_flags *rf)
  {
  	struct task_struct *p, *n;
  
  	lockdep_assert_held(&env->src_rq->lock);
  
  	list_for_each_entry_safe(p, n, &env->src_rq->cfs_tasks, se.group_node) {
  		if (!can_migrate_task(p, env))
  			continue;
  
  		detach_task(p, env, rf);
  
  		/*
  		 * Right now, this is only the second place where
  		 * lb_gained[env->idle] is updated (other is detach_tasks)
  		 * so we can safely collect stats here rather than
  		 * inside detach_tasks().
  		 */
  		schedstat_inc(env->sd->lb_gained[env->idle]);
  		return p;
  	}
  	return NULL;
  }
  
  static const unsigned int sched_nr_migrate_break = 32;
  
  /* must hold runqueue lock for queue se is currently on */
  static struct task_struct *hisi_get_heaviest_task(
  				struct task_struct *p, int cpu)
  {
  	int num_tasks = 5;
  	struct sched_entity *se = &p->se;
  	unsigned long max_util = task_util_est(p), max_preferred_util = 0;
  	struct task_struct *tsk, *max_preferred_tsk = NULL, *max_util_task = p;
  
  	/* The currently running task is not on the runqueue */
  	se = __pick_first_entity(cfs_rq_of(se));
  
  	while (num_tasks && se) {
  		if (!entity_is_task(se)) {
  			se = __pick_next_entity(se);
  			num_tasks--;
  			continue;
  		}
  
  		tsk = task_of(se);
  
  		if (cpumask_test_cpu(cpu, &tsk->cpus_allowed)) {
  			bool boosted = schedtune_task_boost(tsk) > 0;
  			bool prefer_idle = schedtune_prefer_idle(tsk) > 0;
  			unsigned long util = boosted_task_util(tsk);
  
  #ifdef CONFIG_SCHED_HISI_VIP
  			/* prefer vip task */
  			if (tsk->hisi_vip_prio)
  				return tsk;
  #endif
  
  			if (boosted || prefer_idle) {
  				if (util > max_preferred_util) {
  					max_preferred_util = util;;
  					max_preferred_tsk = tsk;
  				}
  			} else {
  				if (util > max_util) {
  					max_util = util;
  					max_util_task = tsk;
  				}
  			}
  		}
  
  		se = __pick_next_entity(se);
  		num_tasks--;
  	}
  
  	return max_preferred_tsk ? max_preferred_tsk : max_util_task;
  }
  
  /*
   * detach_tasks() -- tries to detach up to imbalance weighted load from
   * busiest_rq, as part of a balancing operation within domain "sd".
   *
   * Returns number of detached tasks if successful and 0 otherwise.
   */
  static int detach_tasks(struct lb_env *env, struct rq_flags *rf)
  {
  	struct list_head *tasks = &env->src_rq->cfs_tasks;
  	struct task_struct *p;
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	unsigned long load = 0;
  #else
  	unsigned long load;
  #endif
  	int detached = 0;
  
  	lockdep_assert_held(&env->src_rq->lock);
  
  	if (env->imbalance <= 0)
  		return 0;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	/*
  	 * Src_cpu has an unfinished active load balance job.
  	 *
  	 * src_cpu:
  	 *                  a_heavy_task          ->              stopper
  	 *   rq_lock - decided a migration - rq_unlock |  rq_lock - detach the task - rq_unlock
  	 *
  	 * this_cpu:
  	 *   load_balance - find src_cpu busiest | rq_lock - detach_tasks - rq_unlock | ...
  	 *
  	 * The above two sequence in src_cpu and this_cpu will race when scheduler_tick.
  	 * Always leave the stopper on src_cpu to do the migration.
  	 */
  	if (unlikely(env->src_rq->active_balance))
  		return 0;
  #endif
  
  	while (!list_empty(tasks)) {
  		/*
  		 * We don't want to steal all, otherwise we may be treated likewise,
  		 * which could at worst lead to a livelock crash.
  		 */
  		if (env->idle != CPU_NOT_IDLE && env->src_rq->nr_running <= 1)
  			break;
  
  		p = list_first_entry(tasks, struct task_struct, se.group_node);
  
  		env->loop++;
  		/* We've more or less seen every task there is, call it quits */
  		if (env->loop > env->loop_max)
  			break;
  
  		/* take a breather every nr_migrate tasks */
  		if (env->loop > env->loop_break) {
  			env->loop_break += sched_nr_migrate_break;
  			env->flags |= LBF_NEED_BREAK;
  			break;
  		}
  
  #ifdef CONFIG_HISI_EAS_SCHED
  		if (energy_aware() &&
  		    (capacity_orig_of(env->dst_cpu) > capacity_orig_of(env->src_cpu)) &&
  		    (env->loop <= (env->loop_max >> 1))) {
  			bool boosted, prefer_idle;
  
  			p = hisi_get_heaviest_task(p, env->dst_cpu);
  
  			boosted = schedtune_task_boost(p) > 0;
  			prefer_idle = schedtune_prefer_idle(p) > 0;
  			if (!boosted && !prefer_idle &&
  			    task_util(p) * 100 < capacity_orig_of(env->src_cpu) * up_migration_util_filter)
  				goto next;
  		}
  #endif
  
  		if (!can_migrate_task(p, env))
  			goto next;
  
  		load = task_h_load(p);
  
  		if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed)
  			goto next;
  
  		if ((load / 2) > env->imbalance)
  			goto next;
  
  		detach_task(p, env, rf);
  		list_add(&p->se.group_node, &env->tasks);
  
  		detached++;
  		env->imbalance -= load;
  
  #ifdef CONFIG_PREEMPT
  		/*
  		 * NEWIDLE balancing is a source of latency, so preemptible
  		 * kernels will stop after the first task is detached to minimize
  		 * the critical section.
  		 */
  		if (env->idle == CPU_NEWLY_IDLE)
  			break;
  #endif
  
  		/*
  		 * We only want to steal up to the prescribed amount of
  		 * weighted load.
  		 */
  		if (env->imbalance <= 0)
  			break;
  
  		continue;
  next:
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  		trace_sched_load_balance_skip_tasks(env->src_cpu, env->dst_cpu,
  				env->src_grp_type, p->pid, load,
  				task_util(p),
  				cpumask_bits(&p->cpus_allowed)[0]);
  #endif
  		list_move_tail(&p->se.group_node, tasks);
  	}
  
  	/*
  	 * Right now, this is one of only two places we collect this stat
  	 * so we can safely collect detach_one_task() stats here rather
  	 * than inside detach_one_task().
  	 */
  	schedstat_add(env->sd->lb_gained[env->idle], detached);
  
  	return detached;
  }
  
  /*
   * attach_task() -- attach the task detached by detach_task() to its new rq.
   */
  static void attach_task(struct rq *rq, struct task_struct *p)
  {
  	lockdep_assert_held(&rq->lock);
  
  	BUG_ON(task_rq(p) != rq);
  	activate_task(rq, p, ENQUEUE_NOCLOCK);
  	p->on_rq = TASK_ON_RQ_QUEUED;
  	check_preempt_curr(rq, p, 0);
  }
  
  /*
   * attach_one_task() -- attaches the task returned from detach_one_task() to
   * its new rq.
   */
  static void attach_one_task(struct rq *rq, struct task_struct *p)
  {
  	struct rq_flags rf;
  
  	rq_lock(rq, &rf);
  	update_rq_clock(rq);
  	attach_task(rq, p);
  	rq_unlock(rq, &rf);
  }
  
  /*
   * attach_tasks() -- attaches all tasks detached by detach_tasks() to their
   * new rq.
   */
  static void attach_tasks(struct lb_env *env)
  {
  	struct list_head *tasks = &env->tasks;
  	struct task_struct *p;
  	struct rq_flags rf;
  
  	rq_lock(env->dst_rq, &rf);
  	update_rq_clock(env->dst_rq);
  
  	while (!list_empty(tasks)) {
  		p = list_first_entry(tasks, struct task_struct, se.group_node);
  		list_del_init(&p->se.group_node);
  
  		attach_task(env->dst_rq, p);
  	}
  
  	rq_unlock(env->dst_rq, &rf);
  }
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  
  static void update_blocked_averages(int cpu)
  {
  	struct rq *rq = cpu_rq(cpu);
  	struct cfs_rq *cfs_rq;
  	struct rq_flags rf;
  
  	rq_lock_irqsave(rq, &rf);
  	update_rq_clock(rq);
  
  	/*
  	 * Iterates the task_group tree in a bottom up fashion, see
  	 * list_add_leaf_cfs_rq() for details.
  	 */
  	for_each_leaf_cfs_rq(rq, cfs_rq) {
  		struct sched_entity *se;
  
  		/* throttled entities do not contribute to load */
  		if (throttled_hierarchy(cfs_rq))
  			continue;
  
  		if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq))
  			update_tg_load_avg(cfs_rq, 0);
  
  		/* Propagate pending load changes to the parent, if any: */
  		se = cfs_rq->tg->se[cpu];
  		if (se && !skip_blocked_update(se))
  			update_load_avg(se, 0);
  	}
  	update_rt_rq_load_avg(rq_clock_task(rq), cpu, &rq->rt, 0);
  #ifdef CONFIG_NO_HZ_COMMON
  	rq->last_blocked_load_update_tick = jiffies;
  #endif
  	rq_unlock_irqrestore(rq, &rf);
  }
  
  /*
   * Compute the hierarchical load factor for cfs_rq and all its ascendants.
   * This needs to be done in a top-down fashion because the load of a child
   * group is a fraction of its parents load.
   */
  static void update_cfs_rq_h_load(struct cfs_rq *cfs_rq)
  {
  	struct rq *rq = rq_of(cfs_rq);
  	struct sched_entity *se = cfs_rq->tg->se[cpu_of(rq)];
  	unsigned long now = jiffies;
  	unsigned long load;
  
  	if (cfs_rq->last_h_load_update == now)
  		return;
  
  	WRITE_ONCE(cfs_rq->h_load_next, NULL);
  	for_each_sched_entity(se) {
  		cfs_rq = cfs_rq_of(se);
  		WRITE_ONCE(cfs_rq->h_load_next, se);
  		if (cfs_rq->last_h_load_update == now)
  			break;
  	}
  
  	if (!se) {
  		cfs_rq->h_load = cfs_rq_load_avg(cfs_rq);
  		cfs_rq->last_h_load_update = now;
  	}
  
  	while ((se = READ_ONCE(cfs_rq->h_load_next)) != NULL) {
  		load = cfs_rq->h_load;
  		load = div64_ul(load * se->avg.load_avg,
  			cfs_rq_load_avg(cfs_rq) + 1);
  		cfs_rq = group_cfs_rq(se);
  		cfs_rq->h_load = load;
  		cfs_rq->last_h_load_update = now;
  	}
  }
  
  static unsigned long task_h_load(struct task_struct *p)
  {
  	struct cfs_rq *cfs_rq = task_cfs_rq(p);
  
  	update_cfs_rq_h_load(cfs_rq);
  	return div64_ul(p->se.avg.load_avg * cfs_rq->h_load,
  			cfs_rq_load_avg(cfs_rq) + 1);
  }
  #else
  static inline void update_blocked_averages(int cpu)
  {
  	struct rq *rq = cpu_rq(cpu);
  	struct cfs_rq *cfs_rq = &rq->cfs;
  	struct rq_flags rf;
  
  	rq_lock_irqsave(rq, &rf);
  	update_rq_clock(rq);
  	update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq);
  	update_rt_rq_load_avg(rq_clock_task(rq), cpu, &rq->rt, 0);
  #ifdef CONFIG_NO_HZ_COMMON
  	rq->last_blocked_load_update_tick = jiffies;
  #endif
  	rq_unlock_irqrestore(rq, &rf);
  }
  
  static unsigned long task_h_load(struct task_struct *p)
  {
  	return p->se.avg.load_avg;
  }
  #endif
  
  /********** Helpers for find_busiest_group ************************/
  
  /*
   * sg_lb_stats - stats of a sched_group required for load_balancing
   */
  struct sg_lb_stats {
  	unsigned long avg_load; /*Avg load across the CPUs of the group */
  	unsigned long group_load; /* Total load over the CPUs of the group */
  	unsigned long sum_weighted_load; /* Weighted load of group's tasks */
  	unsigned long load_per_task;
  	unsigned long group_capacity;
  	unsigned long group_util; /* Total utilization of the group */
  	unsigned int sum_nr_running; /* Nr tasks running in the group */
  	unsigned int idle_cpus;
  	unsigned int group_weight;
  	enum group_type group_type;
  	int group_no_capacity;
  	/* A cpu has a task too big for its capacity */
  	unsigned long group_misfit_task_load;
  #ifdef CONFIG_NUMA_BALANCING
  	unsigned int nr_numa_running;
  	unsigned int nr_preferred_running;
  #endif
  #ifdef CONFIG_SCHED_HISI_VIP
  	enum vip_preempt_type vip_preempt_type;
  #endif
  };
  
  /*
   * sd_lb_stats - Structure to store the statistics of a sched_domain
   *		 during load balancing.
   */
  struct sd_lb_stats {
  	struct sched_group *busiest;	/* Busiest group in this sd */
  	struct sched_group *local;	/* Local group in this sd */
  	unsigned long total_running;
  	unsigned long total_load;	/* Total load of all groups in sd */
  	unsigned long total_capacity;	/* Total capacity of all groups in sd */
  	unsigned long total_util;	/* Total util of all groups in sd */
  	unsigned long avg_load;	/* Average load across all groups in sd */
  
  	struct sg_lb_stats busiest_stat;/* Statistics of the busiest group */
  	struct sg_lb_stats local_stat;	/* Statistics of the local group */
  };
  
  static inline void init_sd_lb_stats(struct sd_lb_stats *sds)
  {
  	/*
  	 * Skimp on the clearing to avoid duplicate work. We can avoid clearing
  	 * local_stat because update_sg_lb_stats() does a full clear/assignment.
  	 * We must however clear busiest_stat::avg_load because
  	 * update_sd_pick_busiest() reads this before assignment.
  	 */
  	*sds = (struct sd_lb_stats){
  		.busiest = NULL,
  		.local = NULL,
  		.total_running = 0UL,
  		.total_load = 0UL,
  		.total_capacity = 0UL,
  		.total_util = 0UL,
  		.busiest_stat = {
  			.avg_load = 0UL,
  			.sum_nr_running = 0,
  			.group_type = group_other,
  #ifdef CONFIG_SCHED_HISI_VIP
  			.vip_preempt_type = NO_VIP_PREEMPT,
  #endif
  		},
  	};
  }
  
  /**
   * get_sd_load_idx - Obtain the load index for a given sched domain.
   * @sd: The sched_domain whose load_idx is to be obtained.
   * @idle: The idle status of the CPU for whose sd load_idx is obtained.
   *
   * Return: The load index.
   */
  static inline int get_sd_load_idx(struct sched_domain *sd,
  					enum cpu_idle_type idle)
  {
  	int load_idx;
  
  	switch (idle) {
  	case CPU_NOT_IDLE:
  		load_idx = sd->busy_idx;
  		break;
  
  	case CPU_NEWLY_IDLE:
  		load_idx = sd->newidle_idx;
  		break;
  	default:
  		load_idx = sd->idle_idx;
  		break;
  	}
  
  	return load_idx;
  }
  
  static unsigned long scale_rt_capacity(int cpu)
  {
  	struct rq *rq = cpu_rq(cpu);
  	u64 total, used, age_stamp, avg;
  	s64 delta;
  
  #ifdef CONFIG_SCHED_WALT
  	if (!walt_disabled && sysctl_sched_use_walt_cpu_util)
  		return SCHED_CAPACITY_SCALE;
  #endif
  
  	/*
  	 * Since we're reading these variables without serialization make sure
  	 * we read them once before doing sanity checks on them.
  	 */
  	age_stamp = READ_ONCE(rq->age_stamp);
  	avg = READ_ONCE(rq->rt_avg);
  	delta = __rq_clock_broken(rq) - age_stamp;
  
  	if (unlikely(delta < 0))
  		delta = 0;
  
  	total = sched_avg_period() + delta;
  
  	used = div_u64(avg, total);
  
  	if (likely(used < SCHED_CAPACITY_SCALE))
  		return SCHED_CAPACITY_SCALE - used;
  
  	return 1;
  }
  
  void init_max_cpu_capacity(struct max_cpu_capacity *mcc)
  {
  	raw_spin_lock_init(&mcc->lock);
  	mcc->val = 0;
  	mcc->cpu = -1;
  }
  
  static void update_cpu_capacity(struct sched_domain *sd, int cpu)
  {
  	unsigned long capacity = arch_scale_cpu_capacity(sd, cpu);
  	struct sched_group *sdg = sd->groups;
  	struct max_cpu_capacity *mcc;
  	unsigned long max_capacity;
  	int max_cap_cpu;
  	unsigned long flags;
  
  	cpu_rq(cpu)->cpu_capacity_orig = capacity;
  
  	capacity *= arch_scale_max_freq_capacity(sd, cpu);
  	capacity >>= SCHED_CAPACITY_SHIFT;
  
  	mcc = &cpu_rq(cpu)->rd->max_cpu_capacity;
  
  	raw_spin_lock_irqsave(&mcc->lock, flags);
  	max_capacity = mcc->val;
  	max_cap_cpu = mcc->cpu;
  
  	if ((max_capacity > capacity && max_cap_cpu == cpu) ||
  	    max_capacity < capacity) {
  		mcc->val = capacity;
  		mcc->cpu = cpu;
  #ifdef CONFIG_SCHED_DEBUG
  		raw_spin_unlock_irqrestore(&mcc->lock, flags);
  		printk_deferred(KERN_INFO "CPU%d: update max cpu_capacity %lu\n",
  				cpu, capacity);
  		goto skip_unlock;
  #endif
  	}
  	raw_spin_unlock_irqrestore(&mcc->lock, flags);
  
  skip_unlock: __attribute__ ((unused));
  	capacity *= scale_rt_capacity(cpu);
  	capacity >>= SCHED_CAPACITY_SHIFT;
  
  	if (!capacity)
  		capacity = 1;
  
  	cpu_rq(cpu)->cpu_capacity = capacity;
  	sdg->sgc->capacity = capacity;
  	sdg->sgc->min_capacity = capacity;
  	sdg->sgc->max_capacity = capacity;
  }
  
  void update_group_capacity(struct sched_domain *sd, int cpu)
  {
  	struct sched_domain *child = sd->child;
  	struct sched_group *group, *sdg = sd->groups;
  	unsigned long capacity, min_capacity, max_capacity;
  	unsigned long interval;
  
  	interval = msecs_to_jiffies(sd->balance_interval);
  	interval = clamp(interval, 1UL, max_load_balance_interval);
  	sdg->sgc->next_update = jiffies + interval;
  
  	if (!child) {
  		update_cpu_capacity(sd, cpu);
  		return;
  	}
  
  	capacity = 0;
  	min_capacity = ULONG_MAX;
  	max_capacity = 0;
  
  	if (child->flags & SD_OVERLAP) {
  		/*
  		 * SD_OVERLAP domains cannot assume that child groups
  		 * span the current group.
  		 */
  
  		for_each_cpu(cpu, sched_group_span(sdg)) {
  			struct sched_group_capacity *sgc;
  			struct rq *rq = cpu_rq(cpu);
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  			if (cpu_isolated(cpu))
  				continue;
  #endif
  
  			/*
  			 * build_sched_domains() -> init_sched_groups_capacity()
  			 * gets here before we've attached the domains to the
  			 * runqueues.
  			 *
  			 * Use capacity_of(), which is set irrespective of domains
  			 * in update_cpu_capacity().
  			 *
  			 * This avoids capacity from being 0 and
  			 * causing divide-by-zero issues on boot.
  			 */
  			if (unlikely(!rq->sd)) {
  				capacity += capacity_of(cpu);
  			} else {
  				sgc = rq->sd->groups->sgc;
  				capacity += sgc->capacity;
  			}
  
  			min_capacity = min(capacity, min_capacity);
  			max_capacity = max(capacity, max_capacity);
  		}
  	} else  {
  		/*
  		 * !SD_OVERLAP domains can assume that child groups
  		 * span the current group.
  		 */
  
  		group = child->groups;
  		do {
  			struct sched_group_capacity *sgc = group->sgc;
  #ifdef CONFIG_HISI_CPU_ISOLATION
  			/* Revisit this later. This won't work for MT domain */
  			if (!cpu_isolated(cpumask_first(sched_group_cpus(group)))) {
  				capacity += sgc->capacity;
  				max_capacity = max(sgc->max_capacity, max_capacity);
  				min_capacity = min(sgc->min_capacity, min_capacity);
  			}
  #else
  			capacity += sgc->capacity;
  			min_capacity = min(sgc->min_capacity, min_capacity);
  			max_capacity = max(sgc->max_capacity, max_capacity);
  #endif
  			group = group->next;
  		} while (group != child->groups);
  	}
  
  	sdg->sgc->capacity = capacity;
  	sdg->sgc->min_capacity = min_capacity;
  	sdg->sgc->max_capacity = max_capacity;
  }
  
  /*
   * Check whether the capacity of the rq has been noticeably reduced by side
   * activity. The imbalance_pct is used for the threshold.
   * Return true is the capacity is reduced
   */
  static inline int
  check_cpu_capacity(struct rq *rq, struct sched_domain *sd)
  {
  	return ((rq->cpu_capacity * sd->imbalance_pct) <
  				(rq->cpu_capacity_orig * 100));
  }
  
  /*
   * Group imbalance indicates (and tries to solve) the problem where balancing
   * groups is inadequate due to ->cpus_allowed constraints.
   *
   * Imagine a situation of two groups of 4 cpus each and 4 tasks each with a
   * cpumask covering 1 cpu of the first group and 3 cpus of the second group.
   * Something like:
   *
   *	{ 0 1 2 3 } { 4 5 6 7 }
   *	        *     * * *
   *
   * If we were to balance group-wise we'd place two tasks in the first group and
   * two tasks in the second group. Clearly this is undesired as it will overload
   * cpu 3 and leave one of the cpus in the second group unused.
   *
   * The current solution to this issue is detecting the skew in the first group
   * by noticing the lower domain failed to reach balance and had difficulty
   * moving tasks due to affinity constraints.
   *
   * When this is so detected; this group becomes a candidate for busiest; see
   * update_sd_pick_busiest(). And calculate_imbalance() and
   * find_busiest_group() avoid some of the usual balance conditions to allow it
   * to create an effective group imbalance.
   *
   * This is a somewhat tricky proposition since the next run might not find the
   * group imbalance and decide the groups need to be balanced again. A most
   * subtle and fragile situation.
   */
  
  static inline int sg_imbalanced(struct sched_group *group)
  {
  	return group->sgc->imbalance;
  }
  
  /*
   * group_has_capacity returns true if the group has spare capacity that could
   * be used by some tasks.
   * We consider that a group has spare capacity if the  * number of task is
   * smaller than the number of CPUs or if the utilization is lower than the
   * available capacity for CFS tasks.
   * For the latter, we use a threshold to stabilize the state, to take into
   * account the variance of the tasks' load and to return true if the available
   * capacity in meaningful for the load balancer.
   * As an example, an available capacity of 1% can appear but it doesn't make
   * any benefit for the load balance.
   */
  static inline bool
  group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs)
  {
  	if (sgs->sum_nr_running < sgs->group_weight)
  		return true;
  
  	if ((sgs->group_capacity * 100) >
  			(sgs->group_util * env->sd->imbalance_pct))
  		return true;
  
  	return false;
  }
  
  /*
   *  group_is_overloaded returns true if the group has more tasks than it can
   *  handle.
   *  group_is_overloaded is not equals to !group_has_capacity because a group
   *  with the exact right number of tasks, has no more spare capacity but is not
   *  overloaded so both group_has_capacity and group_is_overloaded return
   *  false.
   */
  static inline bool
  group_is_overloaded(struct lb_env *env, struct sg_lb_stats *sgs)
  {
  	if (sgs->sum_nr_running <= sgs->group_weight)
  		return false;
  
  	if ((sgs->group_capacity * 100) <
  			(sgs->group_util * env->sd->imbalance_pct))
  		return true;
  
  	return false;
  }
  
  /*
   * group_smaller_min_cpu_capacity: Returns true if sched_group sg has smaller
   * per-CPU capacity than sched_group ref.
   */
  static inline bool
  group_smaller_min_cpu_capacity(struct sched_group *sg, struct sched_group *ref)
  {
  #ifdef CONFIG_HISI_EAS_SCHED
  	return sg->sgc->min_capacity < ref->sgc->min_capacity;
  #else
  	return sg->sgc->min_capacity * capacity_margin <
  						ref->sgc->min_capacity * 1024;
  #endif
  }
  
  /*
   * group_smaller_max_cpu_capacity: Returns true if sched_group sg has smaller
   * per-CPU capacity_orig than sched_group ref.
   */
  static inline bool
  group_smaller_max_cpu_capacity(struct sched_group *sg, struct sched_group *ref)
  {
  #ifdef CONFIG_HISI_EAS_SCHED
  	return sg->sgc->max_capacity < ref->sgc->max_capacity;
  #else
  	return sg->sgc->max_capacity * capacity_margin <
  						ref->sgc->max_capacity * 1024;
  #endif
  }
  
  #ifndef CONFIG_HISI_EAS_SCHED
  /*
   * group_similar_cpu_capacity: Returns true if the minimum capacity of the
   * compared groups differ by less than 12.5%.
   */
  static inline bool
  group_similar_cpu_capacity(struct sched_group *sg, struct sched_group *ref)
  {
  	long diff = sg->sgc->min_capacity - ref->sgc->min_capacity;
  	long max = max(sg->sgc->min_capacity, ref->sgc->min_capacity);
  
  	return abs(diff) < max >> 3;
  }
  #endif
  
  static inline enum
  group_type group_classify(struct sched_group *group,
  			  struct sg_lb_stats *sgs)
  {
  	if (sgs->group_no_capacity)
  		return group_overloaded;
  
  	if (sg_imbalanced(group))
  		return group_imbalanced;
  
  	if (sgs->group_misfit_task_load)
  		return group_misfit_task;
  
  #ifdef CONFIG_SCHED_HISI_VIP
  	if (sgs->vip_preempt_type)
  		return group_vip_preempt;
  #endif
  
  	return group_other;
  }
  
  /**
   * update_sg_lb_stats - Update sched_group's statistics for load balancing.
   * @env: The load balancing environment.
   * @group: sched_group whose statistics are to be updated.
   * @load_idx: Load index of sched_domain of this_cpu for load calc.
   * @local_group: Does group contain this_cpu.
   * @sgs: variable to hold the statistics for this group.
   * @overload: Indicate pullable load (e.g. >1 runnable task).
   * @overutilized: Indicate overutilization for any CPU.
   */
  static inline void update_sg_lb_stats(struct lb_env *env,
  			struct sched_group *group, int load_idx,
  			int local_group, struct sg_lb_stats *sgs,
  			bool *overload, bool *overutilized, bool *misfit_task)
  {
  	unsigned long load;
  	int i, nr_running;
  
  	memset(sgs, 0, sizeof(*sgs));
  
  	for_each_cpu_and(i, sched_group_span(group), env->cpus) {
  		struct rq *rq = cpu_rq(i);
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		if (cpu_isolated(i))
  			continue;
  #endif
  
  		/* Bias balancing toward cpus of our domain */
  		if (local_group)
  			load = target_load(i, load_idx);
  		else
  			load = source_load(i, load_idx);
  
  		sgs->group_load += load;
  		sgs->group_util += cpu_util(i);
  		sgs->sum_nr_running += rq->cfs.h_nr_running;
  
  		nr_running = rq->nr_running;
  		if (nr_running > 1)
  			*overload = true;
  
  #ifdef CONFIG_NUMA_BALANCING
  		sgs->nr_numa_running += rq->nr_numa_running;
  		sgs->nr_preferred_running += rq->nr_preferred_running;
  #endif
  		sgs->sum_weighted_load += weighted_cpuload(rq);
  		/*
  		 * No need to call idle_cpu() if nr_running is not 0
  		 */
  		if (!nr_running && idle_cpu(i))
  			sgs->idle_cpus++;
  
  		if (env->sd->flags & SD_ASYM_CPUCAPACITY &&
  		    sgs->group_misfit_task_load < rq->misfit_task_load) {
  			sgs->group_misfit_task_load = rq->misfit_task_load;
  			*overload = 1;
  		}
  
  #ifdef CONFIG_HISI_EAS_SCHED
  		if (cpu_overutilized_for_lb(i)) {
  #else
  		if (cpu_overutilized(i)) {
  #endif
  			*overutilized = true;
  
  			if (rq->misfit_task_load)
  				*misfit_task = true;
  		}
  
  #ifdef CONFIG_SCHED_HISI_VIP
  		if (rq->vip_preempt_type > sgs->vip_preempt_type)
  			sgs->vip_preempt_type = rq->vip_preempt_type;
  #endif
  	}
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	/* Isolated CPU has no weight */
  	if (!group->group_weight) {
  		sgs->group_capacity = 0;
  		sgs->avg_load = 0;
  		sgs->group_no_capacity = 1;
  		sgs->group_type = group_other;
  		sgs->group_weight = 0;
  		sgs->load_per_task = 0;
  		return;
  	}
  #endif
  
  	/* Adjust by relative CPU capacity of the group */
  	sgs->group_capacity = group->sgc->capacity;
  	if (sgs->group_capacity)
  		sgs->avg_load = (sgs->group_load*SCHED_CAPACITY_SCALE) / sgs->group_capacity;
  
  	if (sgs->sum_nr_running)
  		sgs->load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
  
  	sgs->group_weight = group->group_weight;
  
  	sgs->group_no_capacity = group_is_overloaded(env, sgs);
  	sgs->group_type = group_classify(group, sgs);
  }
  
  /**
   * update_sd_pick_busiest - return 1 on busiest group
   * @env: The load balancing environment.
   * @sds: sched_domain statistics
   * @sg: sched_group candidate to be checked for being the busiest
   * @sgs: sched_group statistics
   *
   * Determine if @sg is a busier group than the previously selected
   * busiest group.
   *
   * Return: %true if @sg is a busier group than the previously selected
   * busiest group. %false otherwise.
   */
  static bool update_sd_pick_busiest(struct lb_env *env,
  				   struct sd_lb_stats *sds,
  				   struct sched_group *sg,
  				   struct sg_lb_stats *sgs)
  {
  	struct sg_lb_stats *busiest = &sds->busiest_stat;
  
  	/*
  	 * Don't try to pull misfit tasks we can't help.
  	 * We can use max_capacity here as reduction in capacity on some
  	 * cpus in the group should either be possible to resolve
  	 * internally or be covered by avg_load imbalance (eventually).
  	 */
  	if (sgs->group_type == group_misfit_task &&
  	    (!group_smaller_max_cpu_capacity(sg, sds->local) ||
  	     !group_has_capacity(env, &sds->local_stat)))
  		return false;
  
  	if (sgs->group_type > busiest->group_type)
  		return true;
  
  	if (sgs->group_type < busiest->group_type)
  		return false;
  
  	if (sgs->avg_load <= busiest->avg_load)
  		return false;
  
  	if (!(env->sd->flags & SD_ASYM_CPUCAPACITY))
  		goto asym_packing;
  
  	/*
  	 * Candidate sg has no more than one task per CPU and
  	 * has higher per-CPU capacity. Migrating tasks to less
  	 * capable CPUs may harm throughput. Maximize throughput,
  	 * power/energy consequences are not considered.
  	 */
  	if (sgs->sum_nr_running <= sgs->group_weight &&
  	    group_smaller_min_cpu_capacity(sds->local, sg))
  		return false;
  
  #ifndef CONFIG_HISI_EAS_SCHED
  	/*
  	 * Candidate sg doesn't face any severe imbalance issues so
  	 * don't disturb unless the groups are of similar capacity
  	 * where balancing is more harmless.
  	 */
  	if (sgs->group_type == group_other &&
  		!group_similar_cpu_capacity(sds->local, sg))
  		return false;
  #endif
  
  	/*
  	 * If we have more than one misfit sg go with the biggest misfit.
  	 */
  	if (sgs->group_type == group_misfit_task &&
  	    sgs->group_misfit_task_load < busiest->group_misfit_task_load)
  		return false;
  
  #ifdef CONFIG_SCHED_HISI_VIP
  	if (sgs->group_type == group_vip_preempt &&
  	    sgs->vip_preempt_type <= busiest->vip_preempt_type)
  		return false;
  #endif
  
  asym_packing:
  	/* This is the busiest node in its class. */
  	if (!(env->sd->flags & SD_ASYM_PACKING))
  		return true;
  
  	/* No ASYM_PACKING if target cpu is already busy */
  	if (env->idle == CPU_NOT_IDLE)
  		return true;
  	/*
  	 * ASYM_PACKING needs to move all the work to the highest
  	 * prority CPUs in the group, therefore mark all groups
  	 * of lower priority than ourself as busy.
  	 */
  	if (sgs->sum_nr_running &&
  	    sched_asym_prefer(env->dst_cpu, sg->asym_prefer_cpu)) {
  		if (!sds->busiest)
  			return true;
  
  		/* Prefer to move from lowest priority cpu's work */
  		if (sched_asym_prefer(sds->busiest->asym_prefer_cpu,
  				      sg->asym_prefer_cpu))
  			return true;
  	}
  
  	return false;
  }
  
  #ifdef CONFIG_NUMA_BALANCING
  static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs)
  {
  	if (sgs->sum_nr_running > sgs->nr_numa_running)
  		return regular;
  	if (sgs->sum_nr_running > sgs->nr_preferred_running)
  		return remote;
  	return all;
  }
  
  static inline enum fbq_type fbq_classify_rq(struct rq *rq)
  {
  	if (rq->nr_running > rq->nr_numa_running)
  		return regular;
  	if (rq->nr_running > rq->nr_preferred_running)
  		return remote;
  	return all;
  }
  #else
  static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs)
  {
  	return all;
  }
  
  static inline enum fbq_type fbq_classify_rq(struct rq *rq)
  {
  	return regular;
  }
  #endif /* CONFIG_NUMA_BALANCING */
  
  #ifdef CONFIG_NO_HZ_COMMON
  static struct {
  	cpumask_var_t idle_cpus_mask;
  	atomic_t nr_cpus;
  	unsigned long next_balance;     /* in jiffy units */
  	unsigned long next_update;     /* in jiffy units */
  } nohz ____cacheline_aligned;
  #endif
  
  #define lb_sd_parent(sd) \
  	(sd->parent && sd->parent->groups != sd->parent->groups->next)
  
  /**
   * update_sd_lb_stats - Update sched_domain's statistics for load balancing.
   * @env: The load balancing environment.
   * @sds: variable to hold the statistics for this sched_domain.
   */
  static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sds)
  {
  	struct sched_domain *child = env->sd->child;
  	struct sched_group *sg = env->sd->groups;
  	struct sg_lb_stats *local = &sds->local_stat;
  	struct sg_lb_stats tmp_sgs;
  	int load_idx;
  	bool overload = false, overutilized = false, misfit_task = false;
  	bool prefer_sibling = child && child->flags & SD_PREFER_SIBLING;
  
  #ifdef CONFIG_NO_HZ_COMMON
  	if (env->idle == CPU_NEWLY_IDLE) {
  		int cpu;
  
  		/* Update the stats of NOHZ idle CPUs in the sd */
  		for_each_cpu_and(cpu, sched_domain_span(env->sd),
  				 nohz.idle_cpus_mask) {
  			struct rq *rq = cpu_rq(cpu);
  
  			/* ... Unless we've already done since the last tick */
  			if (time_after(jiffies,
                                         rq->last_blocked_load_update_tick))
  				update_blocked_averages(cpu);
  		}
  	}
  	/*
  	 * If we've just updated all of the NOHZ idle CPUs, then we can push
  	 * back the next nohz.next_update, which will prevent an unnecessary
  	 * wakeup for the nohz stats kick
  	 */
  	if (cpumask_subset(nohz.idle_cpus_mask, sched_domain_span(env->sd)))
  		nohz.next_update = jiffies + LOAD_AVG_PERIOD;
  #endif
  
  	load_idx = get_sd_load_idx(env->sd, env->idle);
  
  	do {
  		struct sg_lb_stats *sgs = &tmp_sgs;
  		int local_group;
  
  		local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(sg));
  		if (local_group) {
  			sds->local = sg;
  			sgs = local;
  
  			if (env->idle != CPU_NEWLY_IDLE ||
  			    time_after_eq(jiffies, sg->sgc->next_update))
  				update_group_capacity(env->sd, env->dst_cpu);
  		}
  
  		update_sg_lb_stats(env, sg, load_idx, local_group, sgs,
  						&overload, &overutilized,
  						&misfit_task);
  
  		if (local_group)
  			goto next_group;
  
  		/*
  		 * In case the child domain prefers tasks go to siblings
  		 * first, lower the sg capacity so that we'll try
  		 * and move all the excess tasks away. We lower the capacity
  		 * of a group only if the local group has the capacity to fit
  		 * these excess tasks. The extra check prevents the case where
  		 * you always pull from the heaviest group when it is already
  		 * under-utilized (possible with a large weight task outweighs
  		 * the tasks on the system).
  		 */
  		if (prefer_sibling && sds->local &&
  		    group_has_capacity(env, local) &&
  		    (sgs->sum_nr_running > local->sum_nr_running + 1)) {
  			sgs->group_no_capacity = 1;
  			sgs->group_type = group_classify(sg, sgs);
  		}
  
  		if (update_sd_pick_busiest(env, sds, sg, sgs)) {
  			sds->busiest = sg;
  			sds->busiest_stat = *sgs;
  		}
  
  next_group:
  		/* Now, start updating sd_lb_stats */
  		sds->total_running += sgs->sum_nr_running;
  		sds->total_load += sgs->group_load;
  		sds->total_capacity += sgs->group_capacity;
  		sds->total_util += sgs->group_util;
  
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  		trace_sched_load_balance_sg_stats(sg->cpumask[0], sgs->group_type,
  					sgs->idle_cpus, sgs->sum_nr_running,
  					sgs->group_load, sgs->group_capacity,
  					sgs->group_util, sgs->group_no_capacity,
  					sgs->load_per_task,
  					sgs->group_misfit_task_load,
  					sds->busiest ? sds->busiest->cpumask[0] : 0);
  #endif
  		sg = sg->next;
  	} while (sg != env->sd->groups);
  
  	if (env->sd->flags & SD_NUMA)
  		env->fbq_type = fbq_classify_group(&sds->busiest_stat);
  
  	env->src_grp_nr_running = sds->busiest_stat.sum_nr_running;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	/*
  	 * We were iterating over env->sd's cpus AND env->cpus.
  	 * Therefore, env->sd is root domain does not mean all root
  	 * domain cpus have been checked, especially when env->cpus is
  	 * subseted because of pinned tasks.
  	 * Since env->cpus was initialized as sched_domain_span(env->sd)
  	 * AND cpu_active_mask, cpumask_equal(env->cpus, cpu_active_mask)
  	 * implies env->sd contains cpu_active_mask. This way we know
  	 * we are at root domain and we were iterating root domain.
  	 */
  	if (cpumask_equal(env->cpus, cpu_active_mask)) {
  #else
  	if (!lb_sd_parent(env->sd)) {
  #endif
  		/* update overload indicator if we are at root domain */
  		if (READ_ONCE(env->dst_rq->rd->overload) != overload)
  			WRITE_ONCE(env->dst_rq->rd->overload, overload);
  	}
  
  	if (overutilized)
  		set_sd_overutilized(env->sd);
  	else
  		clear_sd_overutilized(env->sd);
  
  	/*
  	 * If there is a misfit task in one cpu in this sched_domain
  	 * it is likely that the imbalance cannot be sorted out among
  	 * the cpu's in this sched_domain. In this case set the
  	 * overutilized flag at the parent sched_domain.
  	 */
  	if (misfit_task) {
  		struct sched_domain *sd = env->sd->parent;
  
  		/*
  		 * In case of a misfit task, load balance at the parent
  		 * sched domain level will make sense only if the the cpus
  		 * have a different capacity. If cpus at a domain level have
  		 * the same capacity, the misfit task cannot be well
  		 * accomodated	in any of the cpus and there in no point in
  		 * trying a load balance at this level
  		 */
  		while (sd) {
  			if (sd->flags & SD_ASYM_CPUCAPACITY) {
  				set_sd_overutilized(sd);
  				break;
  			}
  			sd = sd->parent;
  		}
  	}
  
  	/*
  	 * If the domain util is greater that domain capacity, load balancing
  	 * needs to be done at the next sched domain level as well.
  	 */
  	if (lb_sd_parent(env->sd) &&
  	    sds->total_capacity * 1024 < sds->total_util * hisi_sd_capacity_margin(group_first_cpu(sds->local)))
  		set_sd_overutilized(env->sd->parent);
  }
  
  /**
   * check_asym_packing - Check to see if the group is packed into the
   *			sched domain.
   *
   * This is primarily intended to used at the sibling level.  Some
   * cores like POWER7 prefer to use lower numbered SMT threads.  In the
   * case of POWER7, it can move to lower SMT modes only when higher
   * threads are idle.  When in lower SMT modes, the threads will
   * perform better since they share less core resources.  Hence when we
   * have idle threads, we want them to be the higher ones.
   *
   * This packing function is run on idle threads.  It checks to see if
   * the busiest CPU in this domain (core in the P7 case) has a higher
   * CPU number than the packing function is being run on.  Here we are
   * assuming lower CPU number will be equivalent to lower a SMT thread
   * number.
   *
   * Return: 1 when packing is required and a task should be moved to
   * this CPU.  The amount of the imbalance is returned in env->imbalance.
   *
   * @env: The load balancing environment.
   * @sds: Statistics of the sched_domain which is to be packed
   */
  static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds)
  {
  	int busiest_cpu;
  
  	if (!(env->sd->flags & SD_ASYM_PACKING))
  		return 0;
  
  	if (env->idle == CPU_NOT_IDLE)
  		return 0;
  
  	if (!sds->busiest)
  		return 0;
  
  	busiest_cpu = sds->busiest->asym_prefer_cpu;
  	if (sched_asym_prefer(busiest_cpu, env->dst_cpu))
  		return 0;
  
  	env->imbalance = DIV_ROUND_CLOSEST(
  		sds->busiest_stat.avg_load * sds->busiest_stat.group_capacity,
  		SCHED_CAPACITY_SCALE);
  
  	return 1;
  }
  
  /**
   * fix_small_imbalance - Calculate the minor imbalance that exists
   *			amongst the groups of a sched_domain, during
   *			load balancing.
   * @env: The load balancing environment.
   * @sds: Statistics of the sched_domain whose imbalance is to be calculated.
   */
  static inline
  void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
  {
  	unsigned long tmp, capa_now = 0, capa_move = 0;
  	unsigned int imbn = 2;
  	unsigned long scaled_busy_load_per_task;
  	struct sg_lb_stats *local, *busiest;
  
  	local = &sds->local_stat;
  	busiest = &sds->busiest_stat;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (busiest->sum_nr_running >= busiest->group_weight &&
  	    local->sum_nr_running < local->group_weight) {
  		env->imbalance = busiest->load_per_task;
  		return;
  	}
  #endif
  
  	if (!local->sum_nr_running)
  		local->load_per_task = cpu_avg_load_per_task(env->dst_cpu);
  	else if (busiest->load_per_task > local->load_per_task)
  		imbn = 1;
  
  	scaled_busy_load_per_task =
  		(busiest->load_per_task * SCHED_CAPACITY_SCALE) /
  		busiest->group_capacity;
  
  	if (busiest->avg_load + scaled_busy_load_per_task >=
  	    local->avg_load + (scaled_busy_load_per_task * imbn)) {
  		env->imbalance = busiest->load_per_task;
  		return;
  	}
  
  	/*
  	 * OK, we don't have enough imbalance to justify moving tasks,
  	 * however we may be able to increase total CPU capacity used by
  	 * moving them.
  	 */
  
  	capa_now += busiest->group_capacity *
  			min(busiest->load_per_task, busiest->avg_load);
  	capa_now += local->group_capacity *
  			min(local->load_per_task, local->avg_load);
  	capa_now /= SCHED_CAPACITY_SCALE;
  
  	/* Amount of load we'd subtract */
  	if (busiest->avg_load > scaled_busy_load_per_task) {
  		capa_move += busiest->group_capacity *
  			    min(busiest->load_per_task,
  				busiest->avg_load - scaled_busy_load_per_task);
  	}
  
  	/* Amount of load we'd add */
  	if (busiest->avg_load * busiest->group_capacity <
  	    busiest->load_per_task * SCHED_CAPACITY_SCALE) {
  		tmp = (busiest->avg_load * busiest->group_capacity) /
  		      local->group_capacity;
  	} else {
  		tmp = (busiest->load_per_task * SCHED_CAPACITY_SCALE) /
  		      local->group_capacity;
  	}
  	capa_move += local->group_capacity *
  		    min(local->load_per_task, local->avg_load + tmp);
  	capa_move /= SCHED_CAPACITY_SCALE;
  
  	/* Move if we gain throughput */
  	if (capa_move > capa_now) {
  		env->imbalance = busiest->load_per_task;
  		return;
  	}
  
  	/* We can't see throughput improvement with the load-based
  	 * method, but it is possible depending upon group size and
  	 * capacity range that there might still be an underutilized
  	 * cpu available in an asymmetric capacity system. Do one last
  	 * check just in case.
  	 */
  	if (env->sd->flags & SD_ASYM_CPUCAPACITY &&
  	    busiest->group_type == group_overloaded &&
  	    busiest->sum_nr_running > busiest->group_weight &&
  	    local->sum_nr_running < local->group_weight &&
  	    local->group_capacity < busiest->group_capacity)
  		env->imbalance = busiest->load_per_task;
  }
  
  /**
   * calculate_imbalance - Calculate the amount of imbalance present within the
   *			 groups of a given sched_domain during load balance.
   * @env: load balance environment
   * @sds: statistics of the sched_domain whose imbalance is to be calculated.
   */
  static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
  {
  	unsigned long max_pull, load_above_capacity = ~0UL;
  	struct sg_lb_stats *local, *busiest;
  
  	local = &sds->local_stat;
  	busiest = &sds->busiest_stat;
  
  	if (busiest->group_type == group_imbalanced) {
  		/*
  		 * In the group_imb case we cannot rely on group-wide averages
  		 * to ensure cpu-load equilibrium, look at wider averages. XXX
  		 */
  		busiest->load_per_task =
  			min(busiest->load_per_task, sds->avg_load);
  	}
  
  	/*
  	 * Avg load of busiest sg can be less and avg load of local sg can
  	 * be greater than avg load across all sgs of sd because avg load
  	 * factors in sg capacity and sgs with smaller group_type are
  	 * skipped when updating the busiest sg:
  	 */
  	if (busiest->group_type != group_misfit_task &&
  	    (busiest->avg_load <= sds->avg_load ||
  	     local->avg_load >= sds->avg_load)) {
  		env->imbalance = 0;
  		return fix_small_imbalance(env, sds);
  	}
  
  	/*
  	 * If there aren't any idle cpus, avoid creating some.
  	 */
  	if (busiest->group_type == group_overloaded &&
  	    local->group_type   == group_overloaded) {
  		load_above_capacity = busiest->sum_nr_running * SCHED_CAPACITY_SCALE;
  		if (load_above_capacity > busiest->group_capacity) {
  			load_above_capacity -= busiest->group_capacity;
  			load_above_capacity *= scale_load_down(NICE_0_LOAD);
  			load_above_capacity /= busiest->group_capacity;
  		} else
  			load_above_capacity = ~0UL;
  	}
  
  	/*
  	 * We're trying to get all the cpus to the average_load, so we don't
  	 * want to push ourselves above the average load, nor do we wish to
  	 * reduce the max loaded cpu below the average load. At the same time,
  	 * we also don't want to reduce the group load below the group
  	 * capacity. Thus we look for the minimum possible imbalance.
  	 */
  	max_pull = min(busiest->avg_load - sds->avg_load, load_above_capacity);
  
  	/* How much load to actually move to equalise the imbalance */
  	env->imbalance = min(
  		max_pull * busiest->group_capacity,
  		(sds->avg_load - local->avg_load) * local->group_capacity
  	) / SCHED_CAPACITY_SCALE;
  
  	/* Boost imbalance to allow misfit task to be balanced.
  	 * Always do this if we are doing a NEWLY_IDLE balance
  	 * on the assumption that any tasks we have must not be
  	 * long-running (and hence we cannot rely upon load).
  	 * However if we are not idle, we should assume the tasks
  	 * we have are longer running and not override load-based
  	 * calculations above unless we are sure that the local
  	 * group is underutilized.
  	 */
  	if (busiest->group_type == group_misfit_task &&
  	    (env->idle == CPU_NEWLY_IDLE ||
  	     local->sum_nr_running < local->group_weight)) {
  		env->imbalance = max_t(long, env->imbalance,
  				       busiest->group_misfit_task_load);
  	}
  
  	/*
  	 * if *imbalance is less than the average load per runnable task
  	 * there is no guarantee that any tasks will be moved so we'll have
  	 * a think about bumping its value to force at least one task to be
  	 * moved
  	 */
  	if (env->imbalance < busiest->load_per_task)
  		return fix_small_imbalance(env, sds);
  }
  
  /******* find_busiest_group() helpers end here *********************/
  
  /**
   * find_busiest_group - Returns the busiest group within the sched_domain
   * if there is an imbalance.
   *
   * Also calculates the amount of weighted load which should be moved
   * to restore balance.
   *
   * @env: The load balancing environment.
   *
   * Return:	- The busiest group if imbalance exists.
   */
  static struct sched_group *find_busiest_group(struct lb_env *env)
  {
  	struct sg_lb_stats *local, *busiest;
  	struct sd_lb_stats sds;
  	unsigned int hisi_fbg_flag = 0;
  
  	init_sd_lb_stats(&sds);
  
  	/*
  	 * Compute the various statistics relavent for load balancing at
  	 * this level.
  	 */
  	update_sd_lb_stats(env, &sds);
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (sds.busiest_stat.group_capacity == 0 ||
  	    sds.local_stat.group_capacity == 0)
  		goto out_balanced;
  
  	if (energy_aware() && ((env->sd->flags & SD_ASYM_CPUCAPACITY) || env->idle == CPU_NOT_IDLE)) {
  		if (!sd_overutilized(env->sd))
  			goto out_balanced;
  	}
  #else
  	if (energy_aware() && !sd_overutilized(env->sd))
  		goto out_balanced;
  #endif
  
  	local = &sds.local_stat;
  	busiest = &sds.busiest_stat;
  
  	/* ASYM feature bypasses nice load balance check */
  	if (check_asym_packing(env, &sds))
  		return sds.busiest;
  
  	hisi_fbg_flag++;
  	/* There is no busy sibling group to pull tasks from */
  	if (!sds.busiest || busiest->sum_nr_running == 0)
  		goto out_balanced;
  
  	/* XXX broken for overlapping NUMA groups */
  	sds.avg_load = (SCHED_CAPACITY_SCALE * sds.total_load)
  						/ sds.total_capacity;
  
  	hisi_fbg_flag++;
  	/*
  	 * If the busiest group is imbalanced the below checks don't
  	 * work because they assume all things are equal, which typically
  	 * isn't true due to cpus_allowed constraints and the like.
  	 */
  	if (busiest->group_type == group_imbalanced)
  		goto force_balance;
  
  	hisi_fbg_flag++;
  	/*
  	 * When dst_cpu is idle, prevent SMP nice and/or asymmetric group
  	 * capacities from resulting in underutilization due to avg_load.
  	 */
  	if (env->idle != CPU_NOT_IDLE && group_has_capacity(env, local) &&
  	    busiest->group_no_capacity)
  		goto force_balance;
  
  	hisi_fbg_flag++;
  	/* Misfit tasks should be dealt with regardless of the avg load */
  	if (busiest->group_type == group_misfit_task)
  		goto force_balance;
  
  	hisi_fbg_flag++;
  #ifdef CONFIG_SCHED_HISI_VIP
  	if (busiest->group_type == group_vip_preempt &&
  	    env->idle != CPU_NOT_IDLE) {
  		if (busiest->vip_preempt_type > VIP_PREEMPT_OTHER)
  			goto force_balance;
  		/*
  		 * VIP_PREEMPT_OTHER. Do not force_balance it when it's
  		 * an upmigrate.
  		 */
  		if (capacity_orig_of(group_first_cpu(sds.local)) <=
  		    capacity_orig_of(group_first_cpu(sds.busiest)))
  			goto force_balance;
  	}
  #endif
  
  	hisi_fbg_flag++;
  	/*
  	 * If the local group is busier than the selected busiest group
  	 * don't try and pull any tasks.
  	 */
  	if (local->avg_load >= busiest->avg_load)
  		goto out_balanced;
  
  	hisi_fbg_flag++;
  	/*
  	 * Don't pull any tasks if this group is already above the domain
  	 * average load.
  	 */
  	if (local->avg_load >= sds.avg_load)
  		goto out_balanced;
  
  	hisi_fbg_flag++;
  	if (env->idle == CPU_IDLE) {
  #ifdef CONFIG_HISI_EAS_SCHED
  		/*
  		 * Don't hesitate to move runnable tasks from a cpu to
  		 * an idle cpu in the same cluster.
  		 */
  		if ((busiest->sum_nr_running > busiest->group_weight) &&
  		    (env->sd->flags & SD_SHARE_PKG_RESOURCES))
  			goto force_balance;
  #endif
  		/*
  		 * This cpu is idle. If the busiest group is not overloaded
  		 * and there is no imbalance between this and busiest group
  		 * wrt idle cpus, it is balanced. The imbalance becomes
  		 * significant if the diff is greater than 1 otherwise we
  		 * might end up to just move the imbalance on another group
  		 */
  		if ((busiest->group_type != group_overloaded) &&
  				(local->idle_cpus <= (busiest->idle_cpus + 1)))
  			goto out_balanced;
  	} else {
  		/*
  		 * In the CPU_NEWLY_IDLE, CPU_NOT_IDLE cases, use
  		 * imbalance_pct to be conservative.
  		 */
  		if (100 * busiest->avg_load <=
  				env->sd->imbalance_pct * local->avg_load)
  			goto out_balanced;
  	}
  
  	hisi_fbg_flag++;
  
  force_balance:
  	/* Looks like there is an imbalance. Compute it */
  	env->src_grp_type = busiest->group_type;
  	calculate_imbalance(env, &sds);
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	trace_sched_find_busiest_group(env->idle, busiest->group_type,
  				       sched_group_cpus(sds.busiest), hisi_fbg_flag);
  
  	trace_sched_load_balance_stats(sds.busiest->cpumask[0], busiest->group_type,
  				busiest->avg_load, busiest->load_per_task,
  				sds.local->cpumask[0], local->group_type,
  				local->avg_load, local->load_per_task,
  				sds.avg_load, env->imbalance);
  #endif
  	return sds.busiest;
  
  out_balanced:
  	env->imbalance = 0;
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	trace_sched_find_busiest_group(env->idle, -1, cpu_none_mask, hisi_fbg_flag);
  #endif
  	return NULL;
  }
  
  /*
   * find_busiest_queue - find the busiest runqueue among the cpus in group.
   */
  static struct rq *find_busiest_queue(struct lb_env *env,
  				     struct sched_group *group)
  {
  	struct rq *busiest = NULL, *rq;
  	unsigned long busiest_load = 0, busiest_capacity = 1;
  	int i;
  
  	for_each_cpu_and(i, sched_group_span(group), env->cpus) {
  		unsigned long capacity, wl;
  		enum fbq_type rt;
  
  		rq = cpu_rq(i);
  		rt = fbq_classify_rq(rq);
  
  		/*
  		 * We classify groups/runqueues into three groups:
  		 *  - regular: there are !numa tasks
  		 *  - remote:  there are numa tasks that run on the 'wrong' node
  		 *  - all:     there is no distinction
  		 *
  		 * In order to avoid migrating ideally placed numa tasks,
  		 * ignore those when there's better options.
  		 *
  		 * If we ignore the actual busiest queue to migrate another
  		 * task, the next balance pass can still reduce the busiest
  		 * queue by moving tasks around inside the node.
  		 *
  		 * If we cannot move enough load due to this classification
  		 * the next pass will adjust the group classification and
  		 * allow migration of more tasks.
  		 *
  		 * Both cases only affect the total convergence complexity.
  		 */
  		if (rt > env->fbq_type)
  			continue;
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		if (cpu_isolated(i))
  			continue;
  #endif
  
  		/*
  		 * For ASYM_CPUCAPACITY domains with misfit tasks we simply
  		 * seek the "biggest" misfit task.
  		 */
  		if (env->src_grp_type == group_misfit_task) {
  			if (rq->misfit_task_load > busiest_load) {
  				busiest_load = rq->misfit_task_load;
  				busiest = rq;
  			}
  			continue;
  		}
  
  #ifdef CONFIG_SCHED_HISI_VIP
  		if (env->src_grp_type == group_vip_preempt) {
  			if (!busiest ||
  			    rq->vip_preempt_type > busiest->vip_preempt_type)
  				busiest = rq;
  			continue;
  		}
  #endif
  
  		capacity = capacity_of(i);
  
  		/*
  		 * For ASYM_CPUCAPACITY domains, don't pick a cpu that could
  		 * eventually lead to active_balancing high->low capacity.
  		 * Higher per-cpu capacity is considered better than balancing
  		 * average load.
  		 */
  		if (env->sd->flags & SD_ASYM_CPUCAPACITY &&
  		    capacity_of(env->dst_cpu) < capacity &&
  		    rq->nr_running == 1)
  			continue;
  
  		wl = weighted_cpuload(rq);
  
  		/*
  		 * When comparing with imbalance, use weighted_cpuload()
  		 * which is not scaled with the cpu capacity.
  		 */
  
  		if (rq->nr_running == 1 && wl > env->imbalance &&
  		    !check_cpu_capacity(rq, env->sd))
  			continue;
  
  		/*
  		 * For the load comparisons with the other cpu's, consider
  		 * the weighted_cpuload() scaled with the cpu capacity, so
  		 * that the load can be moved away from the cpu that is
  		 * potentially running at a lower capacity.
  		 *
  		 * Thus we're looking for max(wl_i / capacity_i), crosswise
  		 * multiplication to rid ourselves of the division works out
  		 * to: wl_i * capacity_j > wl_j * capacity_i;  where j is
  		 * our previous maximum.
  		 */
  		if (wl * busiest_capacity > busiest_load * capacity) {
  			busiest_load = wl;
  			busiest_capacity = capacity;
  			busiest = rq;
  		}
  	}
  
  	return busiest;
  }
  
  /*
   * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but
   * so long as it is large enough.
   */
  #define MAX_PINNED_INTERVAL	512
  
  static int need_active_balance(struct lb_env *env)
  {
  	struct sched_domain *sd = env->sd;
  
  	if (env->idle == CPU_NEWLY_IDLE) {
  
  		/*
  		 * ASYM_PACKING needs to force migrate tasks from busy but
  		 * lower priority CPUs in order to pack all tasks in the
  		 * highest priority CPUs.
  		 */
  		if ((sd->flags & SD_ASYM_PACKING) &&
  		    sched_asym_prefer(env->dst_cpu, env->src_cpu))
  			return 1;
  	}
  
  	/*
  	 * The dst_cpu is idle and the src_cpu CPU has only 1 CFS task.
  	 * It's worth migrating the task if the src_cpu's capacity is reduced
  	 * because of other sched_class or IRQs if more capacity stays
  	 * available on dst_cpu.
  	 */
  	if ((env->idle != CPU_NOT_IDLE) &&
  	    (env->src_rq->cfs.h_nr_running == 1)) {
  		if ((check_cpu_capacity(env->src_rq, sd)) &&
  		    (capacity_of(env->src_cpu)*sd->imbalance_pct < capacity_of(env->dst_cpu)*100))
  			return 1;
  	}
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if ((env->idle == CPU_NEWLY_IDLE) &&
  	    (capacity_orig_of(env->src_cpu) < capacity_orig_of(env->dst_cpu)) &&
  	    env->src_rq->misfit_task_load)
  		return 1;
  #else
  	if ((capacity_of(env->src_cpu) < capacity_of(env->dst_cpu)) &&
  	    ((capacity_orig_of(env->src_cpu) < capacity_orig_of(env->dst_cpu))) &&
  				env->src_rq->cfs.h_nr_running == 1 &&
  				cpu_overutilized(env->src_cpu) &&
  				!cpu_overutilized(env->dst_cpu)) {
  			return 1;
  	}
  
  	if (env->src_grp_type == group_misfit_task)
  		return 1;
  
  	if (env->src_grp_type == group_overloaded &&
  	    env->src_rq->misfit_task_load)
  		return 1;
  #endif
  
  	return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2);
  }
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  static int group_balance_cpu_not_isolated(struct sched_group *sg)
  {
  	cpumask_t cpus;
  
  	cpumask_andnot(&cpus, group_balance_mask(sg), cpu_isolated_mask);
  	return cpumask_first(&cpus);
  }
  #endif
  
  static int active_load_balance_cpu_stop(void *data);
  
  static int should_we_balance(struct lb_env *env)
  {
  	struct sched_group *sg = env->sd->groups;
  	int cpu, balance_cpu = -1;
  
  	/*
  	 * Ensure the balancing environment is consistent; can happen
  	 * when the softirq triggers 'during' hotplug.
  	 */
  	if (!cpumask_test_cpu(env->dst_cpu, env->cpus))
  		return 0;
  
  	/*
  	 * In the newly idle case, we will allow all the cpu's
  	 * to do the newly idle load balance.
  	 */
  	if (env->idle == CPU_NEWLY_IDLE)
  		return 1;
  
  	/* Try to find first idle cpu */
  	for_each_cpu_and(cpu, group_balance_mask(sg), env->cpus) {
  		if (!idle_cpu(cpu))
  			continue;
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		if (cpu_isolated(cpu))
  			continue;
  #endif
  
  		balance_cpu = cpu;
  		break;
  	}
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	if (balance_cpu == -1)
  		balance_cpu = group_balance_cpu_not_isolated(sg);
  #else
  	if (balance_cpu == -1)
  		balance_cpu = group_balance_cpu(sg);
  #endif
  
  	/*
  	 * First idle cpu or the first cpu(busiest) in this sched group
  	 * is eligible for doing load balancing at this and above domains.
  	 */
  	return balance_cpu == env->dst_cpu;
  }
  
  /*
   * Check this_cpu to ensure it is balanced within domain. Attempt to move
   * tasks if there is an imbalance.
   */
  static int load_balance(int this_cpu, struct rq *this_rq,
  			struct sched_domain *sd, enum cpu_idle_type idle,
  			int *continue_balancing)
  {
  	int ld_moved, cur_ld_moved, active_balance = 0;
  	struct sched_domain *sd_parent = lb_sd_parent(sd) ? sd->parent : NULL;
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	struct sched_group *group = NULL;
  	struct rq *busiest = NULL;
  #else
  	struct sched_group *group;
  	struct rq *busiest;
  #endif
  	struct rq_flags rf;
  	struct cpumask *cpus = this_cpu_cpumask_var_ptr(load_balance_mask);
  
  	struct lb_env env = {
  		.sd		= sd,
  		.dst_cpu	= this_cpu,
  		.dst_rq		= this_rq,
  		.dst_grpmask    = sched_group_span(sd->groups),
  		.idle		= idle,
  		.loop_break	= sched_nr_migrate_break,
  		.cpus		= cpus,
  		.fbq_type	= all,
  		.tasks		= LIST_HEAD_INIT(env.tasks),
  	};
  
  	cpumask_and(cpus, sched_domain_span(sd), cpu_active_mask);
  
  	schedstat_inc(sd->lb_count[idle]);
  
  redo:
  	if (!should_we_balance(&env)) {
  		*continue_balancing = 0;
  		goto out_balanced;
  	}
  
  	group = find_busiest_group(&env);
  	if (!group) {
  		schedstat_inc(sd->lb_nobusyg[idle]);
  		goto out_balanced;
  	}
  
  	busiest = find_busiest_queue(&env, group);
  	if (!busiest) {
  		schedstat_inc(sd->lb_nobusyq[idle]);
  		goto out_balanced;
  	}
  
  	BUG_ON(busiest == env.dst_rq);
  
  	schedstat_add(sd->lb_imbalance[idle], env.imbalance);
  
  	env.src_cpu = busiest->cpu;
  	env.src_rq = busiest;
  
  	ld_moved = 0;
  	if (busiest->nr_running > 1) {
  		/*
  		 * Attempt to move tasks. If find_busiest_group has found
  		 * an imbalance but busiest->nr_running <= 1, the group is
  		 * still unbalanced. ld_moved simply stays zero, so it is
  		 * correctly treated as an imbalance.
  		 */
  		env.flags |= LBF_ALL_PINNED;
  		env.loop_max  = min(sysctl_sched_nr_migrate, busiest->nr_running);
  
  more_balance:
  		rq_lock_irqsave(busiest, &rf);
  		update_rq_clock(busiest);
  
  		/*
  		 * cur_ld_moved - load moved in current iteration
  		 * ld_moved     - cumulative load moved across iterations
  		 */
  		cur_ld_moved = detach_tasks(&env, &rf);
  
  		/*
  		 * We've detached some tasks from busiest_rq. Every
  		 * task is masked "TASK_ON_RQ_MIGRATING", so we can safely
  		 * unlock busiest->lock, and we are able to be sure
  		 * that nobody can manipulate the tasks in parallel.
  		 * See task_rq_lock() family for the details.
  		 */
  
  		rq_unlock(busiest, &rf);
  
  		if (cur_ld_moved) {
  			attach_tasks(&env);
  			ld_moved += cur_ld_moved;
  		}
  
  		local_irq_restore(rf.flags);
  
  		if (env.flags & LBF_NEED_BREAK) {
  			env.flags &= ~LBF_NEED_BREAK;
  			goto more_balance;
  		}
  
  		/*
  		 * Revisit (affine) tasks on src_cpu that couldn't be moved to
  		 * us and move them to an alternate dst_cpu in our sched_group
  		 * where they can run. The upper limit on how many times we
  		 * iterate on same src_cpu is dependent on number of cpus in our
  		 * sched_group.
  		 *
  		 * This changes load balance semantics a bit on who can move
  		 * load to a given_cpu. In addition to the given_cpu itself
  		 * (or a ilb_cpu acting on its behalf where given_cpu is
  		 * nohz-idle), we now have balance_cpu in a position to move
  		 * load to given_cpu. In rare situations, this may cause
  		 * conflicts (balance_cpu and given_cpu/ilb_cpu deciding
  		 * _independently_ and at _same_ time to move some load to
  		 * given_cpu) causing exceess load to be moved to given_cpu.
  		 * This however should not happen so much in practice and
  		 * moreover subsequent load balance cycles should correct the
  		 * excess load moved.
  		 */
  		if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) {
  
  			/* Prevent to re-select dst_cpu via env's cpus */
  			cpumask_clear_cpu(env.dst_cpu, env.cpus);
  
  			env.dst_rq	 = cpu_rq(env.new_dst_cpu);
  			env.dst_cpu	 = env.new_dst_cpu;
  			env.flags	&= ~LBF_DST_PINNED;
  			env.loop	 = 0;
  			env.loop_break	 = sched_nr_migrate_break;
  
  			/*
  			 * Go back to "more_balance" rather than "redo" since we
  			 * need to continue with same src_cpu.
  			 */
  			goto more_balance;
  		}
  
  		/*
  		 * We failed to reach balance because of affinity.
  		 */
  		if (sd_parent) {
  			int *group_imbalance = &sd_parent->groups->sgc->imbalance;
  
  			if ((env.flags & LBF_SOME_PINNED) && env.imbalance > 0)
  				*group_imbalance = 1;
  		}
  
  		/* All tasks on this runqueue were pinned by CPU affinity */
  		if (unlikely(env.flags & LBF_ALL_PINNED)) {
  			cpumask_clear_cpu(cpu_of(busiest), cpus);
  			/*
  			 * Attempting to continue load balancing at the current
  			 * sched_domain level only makes sense if there are
  			 * active CPUs remaining as possible busiest CPUs to
  			 * pull load from which are not contained within the
  			 * destination group that is receiving any migrated
  			 * load.
  			 */
  			if (!cpumask_subset(cpus, env.dst_grpmask)) {
  				env.loop = 0;
  				env.loop_break = sched_nr_migrate_break;
  				goto redo;
  			}
  			goto out_all_pinned;
  		}
  	}
  
  	if (!ld_moved) {
  		schedstat_inc(sd->lb_failed[idle]);
  		/*
  		 * Increment the failure counter only on periodic balance.
  		 * We do not want newidle balance, which can be very
  		 * frequent, pollute the failure counter causing
  		 * excessive cache_hot migrations and active balances.
  		 */
  		if (idle != CPU_NEWLY_IDLE)
  			if (env.src_grp_nr_running > 1)
  				sd->nr_balance_failed++;
  
  		if (need_active_balance(&env)) {
  			unsigned long flags;
  
  			raw_spin_lock_irqsave(&busiest->lock, flags);
  
  #ifdef CONFIG_HISI_EAS_SCHED
  			/*
  			 * The CPUs are marked as reserved if tasks
  			 * are pushed/pulled from other CPUs. In that case,
  			 * bail out from the load balancer.
  			 */
  			if (is_reserved(this_cpu) ||
  			    is_reserved(cpu_of(busiest))) {
  				raw_spin_unlock_irqrestore(&busiest->lock,
  							   flags);
  				*continue_balancing = 0;
  				goto out;
  			}
  #endif
  
  			/* don't kick the active_load_balance_cpu_stop,
  			 * if the curr task on busiest cpu can't be
  			 * moved to this_cpu
  			 */
  			if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) {
  				raw_spin_unlock_irqrestore(&busiest->lock,
  							    flags);
  				env.flags |= LBF_ALL_PINNED;
  				goto out_one_pinned;
  			}
  
  			/*
  			 * ->active_balance synchronizes accesses to
  			 * ->active_balance_work.  Once set, it's cleared
  			 * only after active load balance is finished.
  			 */
  			if (!busiest->active_balance) {
  				busiest->active_balance = 1;
  				busiest->push_cpu = this_cpu;
  				active_balance = 1;
  			}
  			raw_spin_unlock_irqrestore(&busiest->lock, flags);
  
  			if (active_balance) {
  				stop_one_cpu_nowait(cpu_of(busiest),
  					active_load_balance_cpu_stop, busiest,
  					&busiest->active_balance_work);
  			}
  
  			/* We've kicked active balancing, force task migration. */
  			sd->nr_balance_failed = sd->cache_nice_tries+1;
  		}
  	} else {
  		sd->nr_balance_failed = 0;
  #ifdef CONFIG_HISI_EAS_SCHED
  		/* Assumes one 'busiest' cpu that we pulled tasks from */
  		sugov_check_freq_update(this_cpu);
  		sugov_check_freq_update(cpu_of(busiest));
  #endif
  	}
  
  	if (likely(!active_balance)) {
  		/* We were unbalanced, so reset the balancing interval */
  		sd->balance_interval = sd->min_interval;
  	} else {
  		/*
  		 * If we've begun active balancing, start to back off. This
  		 * case may not be covered by the all_pinned logic if there
  		 * is only 1 task on the busy runqueue (because we don't call
  		 * detach_tasks).
  		 */
  		if (sd->balance_interval < sd->max_interval)
  			sd->balance_interval *= 2;
  	}
  
  	goto out;
  
  out_balanced:
  	/*
  	 * We reach balance although we may have faced some affinity
  	 * constraints. Clear the imbalance flag only if other tasks got
  	 * a chance to move and fix the imbalance.
  	 */
  	if (sd_parent && !(env.flags & LBF_ALL_PINNED)) {
  		int *group_imbalance = &sd_parent->groups->sgc->imbalance;
  
  		if (*group_imbalance)
  			*group_imbalance = 0;
  	}
  
  out_all_pinned:
  	/*
  	 * We reach balance because all tasks are pinned at this level so
  	 * we can't migrate them. Let the imbalance flag set so parent level
  	 * can try to migrate them.
  	 */
  	schedstat_inc(sd->lb_balanced[idle]);
  
  	sd->nr_balance_failed = 0;
  
  out_one_pinned:
  	ld_moved = 0;
  
  	/*
  	 * idle_balance() disregards balance intervals, so we could repeatedly
  	 * reach this code, which would lead to balance_interval skyrocketting
  	 * in a short amount of time. Skip the balance_interval increase logic
  	 * to avoid that.
  	 */
  	if (env.idle == CPU_NEWLY_IDLE)
  		goto out;
  
  	/* tune up the balancing interval */
  	if (((env.flags & LBF_ALL_PINNED) &&
  			sd->balance_interval < MAX_PINNED_INTERVAL) ||
  			(sd->balance_interval < sd->max_interval))
  		sd->balance_interval *= 2;
  out:
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	trace_sched_load_balance(this_cpu, idle, *continue_balancing,
  				 group ? group->cpumask[0] : 0,
  				 busiest ? busiest->nr_running : 0,
  				 env.imbalance, env.flags, ld_moved,
  				 sd->balance_interval, active_balance);
  #endif
  	return ld_moved;
  }
  
  static inline unsigned long
  get_sd_balance_interval(struct sched_domain *sd, int cpu_busy)
  {
  	unsigned long interval = sd->balance_interval;
  #ifndef CONFIG_HISI_EAS_SCHED
  	unsigned int cpu;
  #endif
  
  	if (cpu_busy)
  		interval *= sd->busy_factor;
  
  	/* scale ms to jiffies */
  	interval = msecs_to_jiffies(interval);
  	interval = clamp(interval, 1UL, max_load_balance_interval);
  
  #ifndef CONFIG_HISI_EAS_SCHED
  	/*
  	 * For hisi, leave misfit task's migration to check_for_migration
  	 * in scheduler tick.
  	 */
  	/*
  	 * check if sched domain is marked as overutilized
  	 * we ought to only do this on systems which have SD_ASYMCAPACITY
  	 * but we want to do it for all sched domains in those systems
  	 * So for now, just check if overutilized as a proxy.
  	 */
  	/*
  	 * If we are overutilized and we have a misfit task, then
  	 * we want to balance as soon as practically possible, so
  	 * we return an interval of zero.
  	 */
  	if (energy_aware() && sd_overutilized(sd)) {
  		/* we know the root is overutilized, let's check for a misfit task */
  		for_each_cpu(cpu, sched_domain_span(sd)) {
  			if (cpu_rq(cpu)->misfit_task_load)
  				return 1;
  		}
  	}
  #endif
  	return interval;
  }
  
  static inline void
  update_next_balance(struct sched_domain *sd, unsigned long *next_balance)
  {
  	unsigned long interval, next;
  
  	/* used by idle balance, so cpu_busy = 0 */
  	interval = get_sd_balance_interval(sd, 0);
  	next = sd->last_balance + interval;
  
  	if (time_after(*next_balance, next))
  		*next_balance = next;
  }
  
  /*
   * idle_balance is called by schedule() if this_cpu is about to become
   * idle. Attempts to pull tasks from other CPUs.
   */
  static int idle_balance(struct rq *this_rq, struct rq_flags *rf)
  {
  	unsigned long next_balance = jiffies + HZ;
  	int this_cpu = this_rq->cpu;
  	struct sched_domain *sd;
  	int pulled_task = 0;
  	u64 curr_cost = 0;
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	if (cpu_isolated(this_cpu))
  		return 0;
  #endif
  
  	/*
  	 * We must set idle_stamp _before_ calling idle_balance(), such that we
  	 * measure the duration of idle_balance() as idle time.
  	 */
  	this_rq->idle_stamp = rq_clock(this_rq);
  
  	/*
  	 * Do not pull tasks towards !active CPUs...
  	 */
  	if (!cpu_active(this_cpu))
  		return 0;
  
  	/*
  	 * This is OK, because current is on_cpu, which avoids it being picked
  	 * for load-balance and preemption/IRQs are still disabled avoiding
  	 * further scheduler activity on it and we're being very careful to
  	 * re-start the picking loop.
  	 */
  	rq_unpin_lock(this_rq, rf);
  
  	if (this_rq->avg_idle < sysctl_sched_migration_cost ||
  	    !READ_ONCE(this_rq->rd->overload)) {
  		rcu_read_lock();
  		sd = rcu_dereference_check_sched_domain(this_rq->sd);
  		if (sd)
  			update_next_balance(sd, &next_balance);
  		rcu_read_unlock();
  
  		goto out;
  	}
  
  	raw_spin_unlock(&this_rq->lock);
  
  	update_blocked_averages(this_cpu);
  	rcu_read_lock();
  	for_each_domain(this_cpu, sd) {
  		int continue_balancing = 1;
  		u64 t0, domain_cost;
  
  		if (!(sd->flags & SD_LOAD_BALANCE)) {
  			if (time_after_eq(jiffies,
  					  sd->groups->sgc->next_update))
  				update_group_capacity(sd, this_cpu);
  			continue;
  		}
  
  		if (this_rq->avg_idle < curr_cost + sd->max_newidle_lb_cost) {
  			update_next_balance(sd, &next_balance);
  			break;
  		}
  
  		if (sd->flags & SD_BALANCE_NEWIDLE) {
  			t0 = sched_clock_cpu(this_cpu);
  
  			pulled_task = load_balance(this_cpu, this_rq,
  						   sd, CPU_NEWLY_IDLE,
  						   &continue_balancing);
  
  			domain_cost = sched_clock_cpu(this_cpu) - t0;
  			if (domain_cost > sd->max_newidle_lb_cost)
  				sd->max_newidle_lb_cost = domain_cost;
  
  			curr_cost += domain_cost;
  		}
  
  		update_next_balance(sd, &next_balance);
  
  		/*
  		 * Stop searching for tasks to pull if there are
  		 * now runnable tasks on this rq.
  		 */
  		if (pulled_task || this_rq->nr_running > 0)
  			break;
  	}
  	rcu_read_unlock();
  
  	raw_spin_lock(&this_rq->lock);
  
  	if (curr_cost > this_rq->max_idle_balance_cost)
  		this_rq->max_idle_balance_cost = curr_cost;
  
  	/*
  	 * While browsing the domains, we released the rq lock, a task could
  	 * have been enqueued in the meantime. Since we're not going idle,
  	 * pretend we pulled a task.
  	 */
  	if (this_rq->cfs.h_nr_running && !pulled_task)
  		pulled_task = 1;
  
  out:
  	/* Move the next balance forward */
  	if (time_after(this_rq->next_balance, next_balance))
  		this_rq->next_balance = next_balance;
  
  	/* Is there a task of a high priority class? */
  	if (this_rq->nr_running != this_rq->cfs.h_nr_running)
  		pulled_task = -1;
  
  	if (pulled_task)
  		this_rq->idle_stamp = 0;
  
  	rq_repin_lock(this_rq, rf);
  
  	return pulled_task;
  }
  
  /*
   * active_load_balance_cpu_stop is run by cpu stopper. It pushes
   * running tasks off the busiest CPU onto idle CPUs. It requires at
   * least 1 task to be running on each physical CPU where possible, and
   * avoids physical / logical imbalances.
   */
  static int active_load_balance_cpu_stop(void *data)
  {
  	struct rq *busiest_rq = data;
  	int busiest_cpu = cpu_of(busiest_rq);
  	int target_cpu = busiest_rq->push_cpu;
  	struct rq *target_rq = cpu_rq(target_cpu);
  	struct sched_domain *sd;
  	struct task_struct *p = NULL;
  	struct rq_flags rf;
  #ifdef CONFIG_HISI_EAS_SCHED
  	struct task_struct *push_task = busiest_rq->push_task;
  	int push_task_detached = 0;
  	struct lb_env env = {
  		.sd		= NULL,
  		.dst_cpu	= target_cpu,
  		.dst_rq		= target_rq,
  		.src_cpu	= busiest_rq->cpu,
  		.src_rq		= busiest_rq,
  		.idle		= CPU_IDLE,
  		/*
  		 * can_migrate_task() doesn't need to compute new_dst_cpu
  		 * for active balancing. Since we have CPU_IDLE, but no
  		 * @dst_grpmask we need to make that test go away with lying
  		 * about DST_PINNED.
  		 */
  		.flags		= LBF_DST_PINNED,
  	};
  	bool moved = false;
  #endif
  
  	rq_lock_irq(busiest_rq, &rf);
  
  	/*
  	 * Between queueing the stop-work and running it is a hole in which
  	 * CPUs can become inactive. We should not move tasks from or to
  	 * inactive CPUs.
  	 */
  	if (!cpu_active(busiest_cpu) || !cpu_active(target_cpu))
  		goto out_unlock;
  
  	/* make sure the requested cpu hasn't gone down in the meantime */
  	if (unlikely(busiest_cpu != smp_processor_id() ||
  		     !busiest_rq->active_balance))
  		goto out_unlock;
  
  	/* Is there any task to move? */
  	if (busiest_rq->nr_running <= 1)
  		goto out_unlock;
  
  	/*
  	 * This condition is "impossible", if it occurs
  	 * we need to fix it. Originally reported by
  	 * Bjorn Helgaas on a 128-cpu setup.
  	 */
  	BUG_ON(busiest_rq == target_rq);
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (push_task) {
  		if (task_on_rq_queued(push_task) &&
  		    task_cpu(push_task) == busiest_cpu &&
  		    cpu_online(target_cpu)) {
  			update_rq_clock(busiest_rq);
  			detach_task(push_task, &env, &rf);
  			push_task_detached = 1;
  			moved = true;
  		}
  		goto out_unlock;
  	}
  #endif
  
  	/* Search for an sd spanning us and the target CPU. */
  	rcu_read_lock();
  	for_each_domain(target_cpu, sd) {
  		if ((sd->flags & SD_LOAD_BALANCE) &&
  		    cpumask_test_cpu(busiest_cpu, sched_domain_span(sd)))
  				break;
  	}
  
  	if (likely(sd)) {
  #ifdef CONFIG_HISI_EAS_SCHED
  		env.sd = sd;
  #else
  		struct lb_env env = {
  			.sd		= sd,
  			.dst_cpu	= target_cpu,
  			.dst_rq		= target_rq,
  			.src_cpu	= busiest_rq->cpu,
  			.src_rq		= busiest_rq,
  			.idle		= CPU_IDLE,
  			/*
  			 * can_migrate_task() doesn't need to compute new_dst_cpu
  			 * for active balancing. Since we have CPU_IDLE, but no
  			 * @dst_grpmask we need to make that test go away with lying
  			 * about DST_PINNED.
  			 */
  			.flags		= LBF_DST_PINNED,
  		};
  #endif
  
  		schedstat_inc(sd->alb_count);
  		update_rq_clock(busiest_rq);
  
  		p = detach_one_task(&env, &rf);
  		if (p) {
  			schedstat_inc(sd->alb_pushed);
  			/* Active balancing done, reset the failure counter. */
  			sd->nr_balance_failed = 0;
  #ifdef CONFIG_HISI_EAS_SCHED
  			moved = true;
  #endif
  		} else {
  			schedstat_inc(sd->alb_failed);
  		}
  	}
  	rcu_read_unlock();
  out_unlock:
  	busiest_rq->active_balance = 0;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (push_task)
  		busiest_rq->push_task = NULL;
  #endif
  
  	rq_unlock(busiest_rq, &rf);
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (push_task) {
  		if (push_task_detached)
  			attach_one_task(target_rq, push_task);
  		put_task_struct(push_task);
  		clear_reserved(target_cpu);
  	}
  #endif
  
  	if (p)
  		attach_one_task(target_rq, p);
  
  	local_irq_enable();
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (moved) {
  		sugov_check_freq_update(target_cpu);
  		sugov_check_freq_update(busiest_cpu);
  	}
  #endif
  
  	return 0;
  }
  
  static inline int on_null_domain(struct rq *rq)
  {
  	return unlikely(!rcu_dereference_sched(rq->sd));
  }
  
  #ifdef CONFIG_NO_HZ_COMMON
  /*
   * idle load balancing details
   * - When one of the busy CPUs notice that there may be an idle rebalancing
   *   needed, they will kick the idle load balancer, which then does idle
   *   load balancing for all the idle CPUs.
   */
  
  #ifdef CONFIG_HISI_EAS_SCHED
  /*
   * Reset balance_interval at all sched_domain levels of given cpu, so that it
   * honors kick.
   */
  static inline void reset_balance_interval(int cpu)
  {
  	struct sched_domain *sd;
  
  	if (cpu >= nr_cpu_ids)
  		return;
  
  	rcu_read_lock();
  	for_each_domain(cpu, sd)
  		sd->balance_interval = 0;
  	rcu_read_unlock();
  }
  
  #define NOHZ_KICK_ANY		0
  #define NOHZ_KICK_RESTRICT	1
  #define NOHZ_KICK_BOOST		2
  
  static inline int nohz_kick_type(int call_cpu, struct sched_domain *sd)
  {
  	int type = NOHZ_KICK_ANY;
  	int i;
  
  	if (hisi_test_fast_cpu(call_cpu))
  		return NOHZ_KICK_ANY;
  
  #ifdef CONFIG_SCHED_HISI_VIP
  	if (cpu_rq(call_cpu)->vip_preempt_type > VIP_PREEMPT_OTHER)
  		return NOHZ_KICK_ANY;
  #endif
  
  	if (energy_aware() && cpu_rq(call_cpu)->misfit_task_load) {
  		type = NOHZ_KICK_BOOST;
  	} else if (!sd_overutilized(sd) && !cpu_overutilized(call_cpu)) {
  		type = NOHZ_KICK_RESTRICT;
  	} else {
  		for_each_cpu(i, sched_domain_span(sd)) {
  
  			if (cpu_util(i) * hisi_sd_capacity_margin(i) < capacity_orig_of(i) * 1024) {
  				/* Change the kick type to limit to CPUs that
  				 * are of equal or lower capacity.
  				 */
  				type = NOHZ_KICK_RESTRICT;
  				break;
  			}
  		}
  	}
  
  	return type;
  }
  
  static inline int hisi_find_new_ilb(void)
  {
  	struct sched_domain *sd;
  	int call_cpu = smp_processor_id();
  	int type = NOHZ_KICK_ANY;
  	int ilb = nr_cpu_ids;
  	int i;
  
  	rcu_read_lock();
  
  	sd = rcu_dereference_check_sched_domain(cpu_rq(call_cpu)->sd);
  	if (!sd) {
  		rcu_read_unlock();
  		return nr_cpu_ids;
  	}
  
  	type = nohz_kick_type(call_cpu, sd);
  
  	for_each_domain(call_cpu, sd) {
  		for_each_cpu(i, sched_domain_span(sd)) {
  #ifdef CONFIG_HISI_CPU_ISOLATION
  			if (cpu_isolated(i))
  				continue;
  #endif
  			if (idle_cpu(i)) {
  				bool is_bigger_cpu = capacity_orig_of(i) > capacity_orig_of(call_cpu);
  
  				if ((type == NOHZ_KICK_ANY) ||
  				    (type == NOHZ_KICK_BOOST && is_bigger_cpu) ||
  				    (type == NOHZ_KICK_RESTRICT && !is_bigger_cpu)) {
  					ilb = i;
  					break;
  				}
  
  			}
  		}
  
  		if (ilb < nr_cpu_ids)
  			break;
  	}
  
  	rcu_read_unlock();
  
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	trace_sched_hisi_find_new_ilb(type, ilb);
  #endif
  	reset_balance_interval(ilb);
  
  	return ilb;
  }
  #endif
  
  static inline int find_new_ilb(void)
  {
  #ifdef CONFIG_HISI_EAS_SCHED
  	int ilb = hisi_find_new_ilb();
  #elif defined(CONFIG_HISI_CPU_ISOLATION)
  	int ilb;
  	cpumask_t cpumask;
  	cpumask_andnot(&cpumask, nohz.idle_cpus_mask, cpu_isolated_mask);
  	ilb = cpumask_first(&cpumask);
  #else
  	int ilb = cpumask_first(nohz.idle_cpus_mask);
  #endif
  
  	if (ilb < nr_cpu_ids && idle_cpu(ilb))
  		return ilb;
  
  	return nr_cpu_ids;
  }
  
  /*
   * Kick a CPU to do the nohz balancing, if it is time for it. We pick the
   * nohz_load_balancer CPU (if there is one) otherwise fallback to any idle
   * CPU (if there is one).
   */
  static void nohz_balancer_kick(bool only_update)
  {
  	int ilb_cpu;
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	int cpu;
  #endif
  
  	nohz.next_balance++;
  
  	ilb_cpu = find_new_ilb();
  
  	if (ilb_cpu >= nr_cpu_ids)
  		return;
  
  	if (test_and_set_bit(NOHZ_BALANCE_KICK, nohz_flags(ilb_cpu)))
  		return;
  
  	if (only_update)
  		set_bit(NOHZ_STATS_KICK, nohz_flags(ilb_cpu));
  
  	/*
  	 * Use smp_send_reschedule() instead of resched_cpu().
  	 * This way we generate a sched IPI on the target cpu which
  	 * is idle. And the softirq performing nohz idle load balance
  	 * will be run before returning from the IPI.
  	 */
  #ifdef CONFIG_SCHED_HISI_DEBUG_TRACE
  	cpu = smp_processor_id();
  	trace_sched_load_balance_nohz_kick(cpu, ilb_cpu, cpu_overutilized(cpu));
  #endif
  	smp_send_reschedule(ilb_cpu);
  	return;
  }
  
  void nohz_balance_exit_idle(unsigned int cpu)
  {
  	if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
  		/*
  		 * Completely isolated CPUs don't ever set, so we must test.
  		 */
  		if (likely(cpumask_test_cpu(cpu, nohz.idle_cpus_mask))) {
  			cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
  			atomic_dec(&nohz.nr_cpus);
  		}
  		clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
  	}
  }
  
  static inline void set_cpu_sd_state_busy(void)
  {
  	struct sched_domain *sd;
  	int cpu = smp_processor_id();
  
  	rcu_read_lock();
  	sd = rcu_dereference(per_cpu(sd_llc, cpu));
  
  	if (!sd || !sd->nohz_idle)
  		goto unlock;
  	sd->nohz_idle = 0;
  
  	atomic_inc(&sd->shared->nr_busy_cpus);
  unlock:
  	rcu_read_unlock();
  }
  
  void set_cpu_sd_state_idle(void)
  {
  	struct sched_domain *sd;
  	int cpu = smp_processor_id();
  
  	rcu_read_lock();
  	sd = rcu_dereference(per_cpu(sd_llc, cpu));
  
  	if (!sd || sd->nohz_idle)
  		goto unlock;
  	sd->nohz_idle = 1;
  
  	atomic_dec(&sd->shared->nr_busy_cpus);
  unlock:
  	rcu_read_unlock();
  }
  
  /*
   * This routine will record that the cpu is going idle with tick stopped.
   * This info will be used in performing idle load balancing in the future.
   */
  void nohz_balance_enter_idle(int cpu)
  {
  	/*
  	 * If this cpu is going down, then nothing needs to be done.
  	 */
  	if (!cpu_active(cpu))
  		return;
  
  	/* Spare idle load balancing on CPUs that don't want to be disturbed: */
  	if (!is_housekeeping_cpu(cpu))
  		return;
  
  	if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
  		return;
  
  	/*
  	 * If we're a completely isolated CPU, we don't play.
  	 */
  	if (on_null_domain(cpu_rq(cpu)))
  		return;
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	if (cpu_isolated(cpu))
  		return;
  #endif
  
  	cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
  	atomic_inc(&nohz.nr_cpus);
  	set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
  }
  #else
  static inline void nohz_balancer_kick(bool only_update) {}
  #endif
  
  static DEFINE_SPINLOCK(balancing);
  
  /*
   * Scale the max load_balance interval with the number of CPUs in the system.
   * This trades load-balance latency on larger machines for less cross talk.
   */
  void update_max_interval(void)
  {
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_t avail_mask;
  	unsigned long available_cpus;
  
  	cpumask_andnot(&avail_mask, cpu_online_mask, cpu_isolated_mask);
  	available_cpus = (unsigned long)cpumask_weight(&avail_mask);
  
  	max_load_balance_interval = HZ*available_cpus/10;
  #else
  	max_load_balance_interval = HZ*num_online_cpus()/10;
  #endif
  }
  
  /*
   * It checks each scheduling domain to see if it is due to be balanced,
   * and initiates a balancing operation if so.
   *
   * Balancing parameters are set up in init_sched_domains.
   */
  static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
  {
  	int continue_balancing = 1;
  	int cpu = rq->cpu;
  	unsigned long interval;
  	struct sched_domain *sd;
  	/* Earliest time when we have to do rebalance again */
  	unsigned long next_balance = jiffies + 60*HZ;
  	int update_next_balance = 0;
  	int need_serialize, need_decay = 0;
  	u64 max_cost = 0;
  
  	rcu_read_lock();
  	for_each_domain(cpu, sd) {
  		/*
  		 * Decay the newidle max times here because this is a regular
  		 * visit to all the domains. Decay ~1% per second.
  		 */
  		if (time_after(jiffies, sd->next_decay_max_lb_cost)) {
  			sd->max_newidle_lb_cost =
  				(sd->max_newidle_lb_cost * 253) / 256;
  			sd->next_decay_max_lb_cost = jiffies + HZ;
  			need_decay = 1;
  		}
  		max_cost += sd->max_newidle_lb_cost;
  
  #ifdef CONFIG_HISI_EAS_SCHED
  		if (energy_aware() &&
  		    ((sd->flags & SD_ASYM_CPUCAPACITY) ||
  		     (idle == CPU_NOT_IDLE))) {
  			if (!sd_overutilized(sd))
  				continue;
  		}
  #else
  		if (energy_aware() && !sd_overutilized(sd))
  			continue;
  #endif
  
  		if (!(sd->flags & SD_LOAD_BALANCE)) {
  			if (time_after_eq(jiffies,
  					  sd->groups->sgc->next_update))
  				update_group_capacity(sd, cpu);
  			continue;
  		}
  
  		/*
  		 * Stop the load balance at this level. There is another
  		 * CPU in our sched group which is doing load balancing more
  		 * actively.
  		 */
  		if (!continue_balancing) {
  			if (need_decay)
  				continue;
  			break;
  		}
  
  		interval = get_sd_balance_interval(sd, idle != CPU_IDLE);
  
  		need_serialize = sd->flags & SD_SERIALIZE;
  		if (need_serialize) {
  			if (!spin_trylock(&balancing))
  				goto out;
  		}
  
  		if (time_after_eq(jiffies, sd->last_balance + interval)) {
  			if (load_balance(cpu, rq, sd, idle, &continue_balancing)) {
  				/*
  				 * The LBF_DST_PINNED logic could have changed
  				 * env->dst_cpu, so we can't know our idle
  				 * state even if we migrated tasks. Update it.
  				 */
  				idle = idle_cpu(cpu) ? CPU_IDLE : CPU_NOT_IDLE;
  			}
  			sd->last_balance = jiffies;
  			interval = get_sd_balance_interval(sd, idle != CPU_IDLE);
  		}
  		if (need_serialize)
  			spin_unlock(&balancing);
  out:
  		if (time_after(next_balance, sd->last_balance + interval)) {
  			next_balance = sd->last_balance + interval;
  			update_next_balance = 1;
  		}
  	}
  	if (need_decay) {
  		/*
  		 * Ensure the rq-wide value also decays but keep it at a
  		 * reasonable floor to avoid funnies with rq->avg_idle.
  		 */
  		rq->max_idle_balance_cost =
  			max((u64)sysctl_sched_migration_cost, max_cost);
  	}
  	rcu_read_unlock();
  
  	/*
  	 * next_balance will be updated only when there is a need.
  	 * When the cpu is attached to null domain for ex, it will not be
  	 * updated.
  	 */
  	if (likely(update_next_balance)) {
  		rq->next_balance = next_balance;
  
  #ifdef CONFIG_NO_HZ_COMMON
  		/*
  		 * If this CPU has been elected to perform the nohz idle
  		 * balance. Other idle CPUs have already rebalanced with
  		 * nohz_idle_balance() and nohz.next_balance has been
  		 * updated accordingly. This CPU is now running the idle load
  		 * balance for itself and we need to update the
  		 * nohz.next_balance accordingly.
  		 */
  		if ((idle == CPU_IDLE) && time_after(nohz.next_balance, rq->next_balance))
  			nohz.next_balance = rq->next_balance;
  #endif
  	}
  }
  
  #ifdef CONFIG_NO_HZ_COMMON
  /*
   * In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the
   * rebalancing for all the cpus for whom scheduler ticks are stopped.
   */
  static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
  {
  	int this_cpu = this_rq->cpu;
  	struct rq *rq;
  	struct sched_domain *sd;
  	int balance_cpu;
  	/* Earliest time when we have to do rebalance again */
  	unsigned long next_balance = jiffies + 60*HZ;
  	int update_next_balance = 0;
  
  	if (idle != CPU_IDLE ||
  	    !test_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu)))
  		goto end;
  
  	/*
  	 * This cpu is going to update the blocked load of idle CPUs either
  	 * before doing a rebalancing or just to keep metrics up to date. we
  	 * can safely update the next update timestamp
  	 */
  	rcu_read_lock();
  	sd = rcu_dereference(this_rq->sd);
  	/*
  	 * Check whether there is a sched_domain available for this cpu.
  	 * The last other cpu can have been unplugged since the ILB has been
  	 * triggered and the sched_domain can now be null. The idle balance
  	 * sequence will quickly be aborted as there is no more idle CPUs
  	 */
  	if (sd)
  		nohz.next_update = jiffies + msecs_to_jiffies(LOAD_AVG_PERIOD);
  	rcu_read_unlock();
  
  	for_each_cpu(balance_cpu, nohz.idle_cpus_mask) {
  #ifdef CONFIG_HISI_CPU_ISOLATION
  		if (cpu_isolated(balance_cpu))
  			continue;
  #endif
  
  		if (balance_cpu == this_cpu || !idle_cpu(balance_cpu))
  			continue;
  
  		/*
  		 * If this cpu gets work to do, stop the load balancing
  		 * work being done for other cpus. Next load
  		 * balancing owner will pick it up.
  		 */
  		if (need_resched())
  			break;
  
  		rq = cpu_rq(balance_cpu);
  
  		/*
  		 * If time for next balance is due,
  		 * do the balance.
  		 */
  		if (time_after_eq(jiffies, rq->next_balance)) {
  			struct rq_flags rf;
  
  			rq_lock_irq(rq, &rf);
  			update_rq_clock(rq);
  			cpu_load_update_idle(rq);
  			rq_unlock_irq(rq, &rf);
  
  			update_blocked_averages(balance_cpu);
  			/*
  			 * This idle load balance softirq may have been
  			 * triggered only to update the blocked load and shares
  			 * of idle CPUs (which we have just done for
  			 * balance_cpu). In that case skip the actual balance.
  			 */
  			if (!test_bit(NOHZ_STATS_KICK, nohz_flags(this_cpu)))
  				rebalance_domains(rq, idle);
  		}
  
  		if (time_after(next_balance, rq->next_balance)) {
  			next_balance = rq->next_balance;
  			update_next_balance = 1;
  		}
  	}
  
  	/*
  	 * next_balance will be updated only when there is a need.
  	 * When the CPU is attached to null domain for ex, it will not be
  	 * updated.
  	 */
  	if (likely(update_next_balance))
  		nohz.next_balance = next_balance;
  end:
  	clear_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu));
  }
  
  /*
   * Current heuristic for kicking the idle load balancer in the presence
   * of an idle cpu in the system.
   *   - This rq has more than one task.
   *   - This rq has at least one CFS task and the capacity of the CPU is
   *     significantly reduced because of RT tasks or IRQs.
   *   - At parent of LLC scheduler domain level, this cpu's scheduler group has
   *     multiple busy cpu.
   *   - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler
   *     domain span are idle.
   */
  static inline bool nohz_kick_needed(struct rq *rq, bool only_update)
  {
  	unsigned long now = jiffies;
  	struct sched_domain_shared *sds;
  	struct sched_domain *sd;
  	int nr_busy, i, cpu = rq->cpu;
  	bool kick = false;
  #if defined(CONFIG_HISI_CPU_ISOLATION) && !defined(CONFIG_HISI_EAS_SCHED)
  	cpumask_t cpumask;
  #endif
  
  #ifdef CONFIG_SCHED_HISI_USE_WALT
  	/* When use walt, there's no need for "force update of blocked
  	 * load of idle cpus". */
  	if (only_update)
  		return false;
  #endif
  
  	if (unlikely(rq->idle_balance) && !only_update)
  		return false;
  
         /*
  	* We may be recently in ticked or tickless idle mode. At the first
  	* busy tick after returning from idle, we will update the busy stats.
  	*/
  	set_cpu_sd_state_busy();
  	nohz_balance_exit_idle(cpu);
  
  #ifndef CONFIG_HISI_EAS_SCHED
  	/*
  	 * None are in tickless mode and hence no need for NOHZ idle load
  	 * balancing.
  	 */
  	if (likely(!atomic_read(&nohz.nr_cpus)))
  		return false;
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	cpumask_andnot(&cpumask, nohz.idle_cpus_mask, cpu_isolated_mask);
  	if (cpumask_empty(&cpumask))
  		return false;
  #endif
  #endif
  
  	if (only_update) {
  		if (time_before(now, nohz.next_update))
  			return false;
  		else
  			return true;
  	}
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	if (rq->nr_running >= 2)
  		return true;
  #endif
  
  	if (time_before(now, nohz.next_balance))
  		return false;
  
  	if (rq->nr_running >= 2 &&
  	    (!energy_aware() || cpu_overutilized(cpu)))
  		return true;
  
  	/* Do idle load balance if there have misfit task */
  	if (energy_aware())
  		return rq->misfit_task_load;
  
  	rcu_read_lock();
  	sds = rcu_dereference(per_cpu(sd_llc_shared, cpu));
  	if (sds && !energy_aware()) {
  		/*
  		 * XXX: write a coherent comment on why we do this.
  		 * See also: http://lkml.kernel.org/r/20111202010832.602203411@sbsiddha-desk.sc.intel.com
  		 */
  		nr_busy = atomic_read(&sds->nr_busy_cpus);
  		if (nr_busy > 1) {
  			kick = true;
  			goto unlock;
  		}
  
  	}
  
  	sd = rcu_dereference(rq->sd);
  	if (sd) {
  		if ((rq->cfs.h_nr_running >= 1) &&
  				check_cpu_capacity(rq, sd)) {
  			kick = true;
  			goto unlock;
  		}
  	}
  
  	sd = rcu_dereference(per_cpu(sd_asym, cpu));
  	if (sd) {
  		for_each_cpu(i, sched_domain_span(sd)) {
  			if (i == cpu ||
  			    !cpumask_test_cpu(i, nohz.idle_cpus_mask))
  				continue;
  
  			if (sched_asym_prefer(i, cpu)) {
  				kick = true;
  				goto unlock;
  			}
  		}
  	}
  unlock:
  	rcu_read_unlock();
  	return kick;
  }
  #else
  static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) { }
  static inline bool nohz_kick_needed(struct rq *rq, bool only_update) { return false; }
  #endif
  
  /*
   * run_rebalance_domains is triggered when needed from the scheduler tick.
   * Also triggered for nohz idle balancing (with nohz_balancing_kick set).
   */
  static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
  {
  	struct rq *this_rq = this_rq();
  	enum cpu_idle_type idle = this_rq->idle_balance ?
  						CPU_IDLE : CPU_NOT_IDLE;
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	if (cpu_isolated(this_rq->cpu))
  		return;
  #endif
  
  	/*
  	 * If this cpu has a pending nohz_balance_kick, then do the
  	 * balancing on behalf of the other idle cpus whose ticks are
  	 * stopped. Do nohz_idle_balance *before* rebalance_domains to
  	 * give the idle cpus a chance to load balance. Else we may
  	 * load balance only within the local sched_domain hierarchy
  	 * and abort nohz_idle_balance altogether if we pull some load.
  	 */
  	nohz_idle_balance(this_rq, idle);
  	update_blocked_averages(this_rq->cpu);
  #ifdef CONFIG_NO_HZ_COMMON
  	if (!test_bit(NOHZ_STATS_KICK, nohz_flags(this_rq->cpu)))
  		rebalance_domains(this_rq, idle);
  	clear_bit(NOHZ_STATS_KICK, nohz_flags(this_rq->cpu));
  #else
  	rebalance_domains(this_rq, idle);
  #endif
  }
  
  /*
   * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
   */
  void trigger_load_balance(struct rq *rq)
  {
  	/* Don't need to rebalance while attached to NULL domain */
  	if (unlikely(on_null_domain(rq)))
  		return;
  
  #ifdef CONFIG_HISI_CPU_ISOLATION
  	if (cpu_isolated(cpu_of(rq)))
  		return;
  #endif
  
  	if (time_after_eq(jiffies, rq->next_balance))
  		raise_softirq(SCHED_SOFTIRQ);
  #ifdef CONFIG_NO_HZ_COMMON
  	if (nohz_kick_needed(rq, false))
  		nohz_balancer_kick(false);
  #endif
  }
  
  static void rq_online_fair(struct rq *rq)
  {
  	update_sysctl();
  
  	update_runtime_enabled(rq);
  }
  
  static void rq_offline_fair(struct rq *rq)
  {
  	update_sysctl();
  
  	/* Ensure any throttled groups are reachable by pick_next_task */
  	unthrottle_offline_cfs_rqs(rq);
  }
  
  #ifdef CONFIG_SCHED_HISI_RUNNING_TASK_ROTATION
  struct walt_rotate_work {
  	struct work_struct w;
  	struct task_struct *src_task;
  	struct task_struct *dst_task;
  	int src_cpu;
  	int dst_cpu;
  };
  
  static DEFINE_PER_CPU(struct walt_rotate_work, walt_rotate_works);
  
  static void walt_rotate_work_func(struct work_struct *work)
  {
  	struct walt_rotate_work *wr = container_of(work,
  				struct walt_rotate_work, w);
  
  	migrate_swap(wr->src_task, wr->dst_task);
  
  	put_task_struct(wr->src_task);
  	put_task_struct(wr->dst_task);
  
  	clear_reserved(wr->src_cpu);
  	clear_reserved(wr->dst_cpu);
  }
  
  void walt_rotate_work_init(int cpu)
  {
  	struct walt_rotate_work *wr = &per_cpu(walt_rotate_works, cpu);
  
  	INIT_WORK(&wr->w, walt_rotate_work_func);
  }
  
  unsigned int sysctl_sched_walt_rotate_big_tasks = 1;
  unsigned int walt_rotation_enabled;
  
  void walt_rotation_checkpoint(unsigned int nr_big)
  {
  	if (!sysctl_sched_walt_rotate_big_tasks) {
  		walt_rotation_enabled = 0;
  		return;
  	}
  
  	walt_rotation_enabled = nr_big >= num_possible_cpus();
  
  	trace_walt_rotation_checkpoint(nr_big, walt_rotation_enabled);
  }
  
  #define WALT_ROTATION_THRESHOLD_NS	19000000
  static void walt_check_for_rotation(struct rq *src_rq)
  {
  	u64 wallclock, wait, max_wait = 0, run, max_run = 0;
  	int deserved_cpu = nr_cpu_ids, dst_cpu = nr_cpu_ids;
  	int i, src_cpu = cpu_of(src_rq);
  	struct rq *dst_rq;
  	struct walt_rotate_work *wr = NULL;
  	struct cpumask slow_cpus;
  
  	if (!walt_rotation_enabled)
  		return;
  
  	hisi_get_slow_cpus(&slow_cpus);
  
  	if (!cpumask_test_cpu(src_cpu, &slow_cpus))
  		return;
  
  	wallclock = walt_ktime_clock();
  
  	for_each_cpu(i, &slow_cpus) {
  		struct rq *rq = cpu_rq(i);
  
  		if (is_reserved(i))
  			continue;
  
  		if (!rq->misfit_task_load ||
  		    rq->curr->sched_class != &fair_sched_class)
  			continue;
  
  		wait = wallclock - rq->curr->last_enqueued_ts;
  		if (wait > max_wait) {
  			max_wait = wait;
  			deserved_cpu = i;
  		}
  	}
  
  	if (deserved_cpu != src_cpu)
  		return;
  
  	for_each_cpu_not(i, &slow_cpus) {
  		struct rq *rq = cpu_rq(i);
  
  		if (is_reserved(i))
  			continue;
  
  		if (rq->curr->sched_class != &fair_sched_class)
  			continue;
  
  		if (rq->nr_running > 1)
  			continue;
  
  		run = wallclock - rq->curr->last_enqueued_ts;
  
  		if (run < WALT_ROTATION_THRESHOLD_NS)
  			continue;
  
  		if (run > max_run) {
  			max_run = run;
  			dst_cpu = i;
  		}
  	}
  
  	if (dst_cpu == nr_cpu_ids)
  		return;
  
  	dst_rq = cpu_rq(dst_cpu);
  
  	double_rq_lock(src_rq, dst_rq);
  	if (dst_rq->curr->sched_class == &fair_sched_class) {
  		get_task_struct(src_rq->curr);
  		get_task_struct(dst_rq->curr);
  
  		mark_reserved(src_cpu);
  		mark_reserved(dst_cpu);
  		wr = &per_cpu(walt_rotate_works, src_cpu);
  
  		wr->src_task = src_rq->curr;
  		wr->dst_task = dst_rq->curr;
  
  		wr->src_cpu = src_cpu;
  		wr->dst_cpu = dst_cpu;
  	}
  	double_rq_unlock(src_rq, dst_rq);
  
  	if (wr)
  		queue_work_on(src_cpu, system_highpri_wq, &wr->w);
  }
  #else /* CONFIG_SCHED_HISI_RUNNING_TASK_ROTATION */
  static inline void walt_check_for_rotation(struct rq *rq) { }
  #endif /* CONFIG_SCHED_HISI_RUNNING_TASK_ROTATION */
  
  #ifdef CONFIG_HISI_EAS_SCHED
  static int
  find_max_idle_cpu(struct task_struct *p)
  {
  	int i, max_cap_cpu = -1;
  	unsigned long max_cap = 0;
  
  	for_each_cpu(i, &p->cpus_allowed) {
  		unsigned long cap;
  
  		if (!idle_cpu(i))
  			continue;
  
  		if (skip_cpu(i))
  			continue;
  
  		cap = capacity_orig_of(i);
  		if (cap > max_cap) {
  			max_cap = cap;
  			max_cap_cpu = i;
  		}
  	}
  
  	return max_cap_cpu;
  }
  
  static inline int
  kick_active_balance(struct rq *rq, struct task_struct *p, int new_cpu)
  {
  	int rc = 0;
  
  	if (cpu_of(rq) == new_cpu)
  		return rc;
  
  	/* Invoke active balance to force migrate currently running task */
  	raw_spin_lock(&rq->lock);
  #ifdef CONFIG_HISI_RT_ACTIVE_LB
  	if (!rq->active_balance && !rq->rt_active_balance) {
  #else
  	if (!rq->active_balance) {
  #endif
  		rq->active_balance = 1;
  		rq->push_cpu = new_cpu;
  		get_task_struct(p);
  		rq->push_task = p;
  		rc = 1;
  	}
  	raw_spin_unlock(&rq->lock);
  
  	return rc;
  }
  
  static DEFINE_RAW_SPINLOCK(migration_lock);
  void check_for_migration(struct rq *rq, struct task_struct *p)
  {
  	int new_cpu;
  	int active_balance;
  	int cpu = task_cpu(p);
  #ifdef CONFIG_HISI_RTG
  	struct related_thread_group *grp = NULL;
  #endif
  
  	if (rq->misfit_task_load) {
  		if (rq->curr->state != TASK_RUNNING ||
  		    rq->curr->nr_cpus_allowed == 1)
  			return;
  
  		raw_spin_lock(&migration_lock);
  
  #ifdef CONFIG_SCHED_HISI_VIP
  		if (p->hisi_vip_prio) {
  			new_cpu = find_vip_cpu(p);
  			if (new_cpu != -1 &&
  			    capacity_orig_of(new_cpu) > capacity_orig_of(cpu))
  				goto do_active_balance;
  			else
  				goto out_unlock;
  		}
  #endif
  
  		rcu_read_lock();
  #ifdef CONFIG_HISI_RTG
  		grp = task_related_thread_group(p);
  		if (grp && grp->preferred_cluster) {
  			new_cpu = find_rtg_cpu(p, &grp->preferred_cluster->cpus);
  
  			/* Inside rcu lock. Release it and goto the choice. */
  			rcu_read_unlock();
  			if (new_cpu != -1 &&
  			    capacity_orig_of(new_cpu) > capacity_orig_of(cpu))
  				goto do_active_balance;
  			else
  				goto out_unlock;
  		}
  #endif
  
  		new_cpu = find_energy_efficient_cpu(NULL, p, cpu, cpu, 0);
  		rcu_read_unlock();
  		if (new_cpu != -1 &&
  		    capacity_orig_of(new_cpu) > capacity_orig_of(cpu))
  			goto do_active_balance;
  
  		/*
  		 * In case of a very big task running on little core, fbt()
  		 * might treat an idle middle core as insufficient. However,
  		 * a larger capacity idle core is always welcomed.
  		 */
  		new_cpu = find_max_idle_cpu(p);
  		if (new_cpu != -1 &&
  		    capacity_orig_of(new_cpu) > capacity_orig_of(cpu))
  			goto do_active_balance;
  
  		/* No upmigration possible. Check for rotation */
  		walt_check_for_rotation(rq);
  		goto out_unlock;
  
  do_active_balance:
  		/* Try active balance p to new_cpu */
  		active_balance = kick_active_balance(rq, p, new_cpu);
  		if (active_balance) {
  			mark_reserved(new_cpu);
  			raw_spin_unlock(&migration_lock);
  
  			stop_one_cpu_nowait(cpu,
  					active_load_balance_cpu_stop,
  					rq, &rq->active_balance_work);
  			return;
  		}
  
  out_unlock:
  		raw_spin_unlock(&migration_lock);
  	}
  }
  #endif /* CONFIG_HISI_EAS_SCHED */
  
  #endif /* CONFIG_SMP */
  
  /*
   * scheduler tick hitting a task of our scheduling class:
   */
  static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
  {
  	struct cfs_rq *cfs_rq;
  	struct sched_entity *se = &curr->se;
  
  	for_each_sched_entity(se) {
  		cfs_rq = cfs_rq_of(se);
  		entity_tick(cfs_rq, se, queued);
  	}
  
  	if (static_branch_unlikely(&sched_numa_balancing))
  		task_tick_numa(rq, curr);
  
  	update_misfit_status(curr, rq);
  
  #ifdef CONFIG_HISI_EAS_SCHED
  	/*
  	 * If task has been enqueued long enough, remark rq as misfit here.
  	 * Update_cfs_nr_heavy_running() & check_for_migration() will
  	 * unisolate big core and try to upmigrate the task for us later.
  	 */
  	check_force_upmigrate(curr, rq);
  #endif
  
  #ifdef CONFIG_HISI_CORE_CTRL
  	update_cfs_nr_heavy_running(rq, curr);
  #endif
  
  	update_overutilized_status(rq);
  }
  
  /*
   * called on fork with the child task as argument from the parent's context
   *  - child not yet on the tasklist
   *  - preemption disabled
   */
  static void task_fork_fair(struct task_struct *p)
  {
  	struct cfs_rq *cfs_rq;
  	struct sched_entity *se = &p->se, *curr;
  	struct rq *rq = this_rq();
  	struct rq_flags rf;
  
  	rq_lock(rq, &rf);
  	update_rq_clock(rq);
  
  	cfs_rq = task_cfs_rq(current);
  	curr = cfs_rq->curr;
  	if (curr) {
  		update_curr(cfs_rq);
  		se->vruntime = curr->vruntime;
  	}
  	place_entity(cfs_rq, se, 1);
  
  	if (sysctl_sched_child_runs_first && curr && entity_before(curr, se)) {
  		/*
  		 * Upon rescheduling, sched_class::put_prev_task() will place
  		 * 'current' within the tree based on its new key value.
  		 */
  		swap(curr->vruntime, se->vruntime);
  		resched_curr(rq);
  	}
  
  	se->vruntime -= cfs_rq->min_vruntime;
  	rq_unlock(rq, &rf);
  }
  
  /*
   * Priority of the task has changed. Check to see if we preempt
   * the current task.
   */
  static void
  prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio)
  {
  	if (!task_on_rq_queued(p))
  		return;
  
  	/*
  	 * Reschedule if we are currently running on this runqueue and
  	 * our priority decreased, or if we are not currently running on
  	 * this runqueue and our priority is higher than the current's
  	 */
  	if (rq->curr == p) {
  		if (p->prio > oldprio)
  			resched_curr(rq);
  	} else
  		check_preempt_curr(rq, p, 0);
  }
  
  static inline bool vruntime_normalized(struct task_struct *p)
  {
  	struct sched_entity *se = &p->se;
  
  	/*
  	 * In both the TASK_ON_RQ_QUEUED and TASK_ON_RQ_MIGRATING cases,
  	 * the dequeue_entity(.flags=0) will already have normalized the
  	 * vruntime.
  	 */
  	if (p->on_rq)
  		return true;
  
  	/*
  	 * When !on_rq, vruntime of the task has usually NOT been normalized.
  	 * But there are some cases where it has already been normalized:
  	 *
  	 * - A forked child which is waiting for being woken up by
  	 *   wake_up_new_task().
  	 * - A task which has been woken up by try_to_wake_up() and
  	 *   waiting for actually being woken up by sched_ttwu_pending().
  	 */
  	if (!se->sum_exec_runtime ||
  	    (p->state == TASK_WAKING && p->sched_remote_wakeup))
  		return true;
  
  	return false;
  }
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  /*
   * Propagate the changes of the sched_entity across the tg tree to make it
   * visible to the root
   */
  static void propagate_entity_cfs_rq(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq;
  
  	/* Start to propagate at parent */
  	se = se->parent;
  
  	for_each_sched_entity(se) {
  		cfs_rq = cfs_rq_of(se);
  
  		if (cfs_rq_throttled(cfs_rq))
  			break;
  
  		update_load_avg(se, UPDATE_TG);
  	}
  }
  #else
  static void propagate_entity_cfs_rq(struct sched_entity *se) { }
  #endif
  
  static void detach_entity_cfs_rq(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  
  	/* Catch up with the cfs_rq and remove our load when we leave */
  	update_load_avg(se, 0);
  	detach_entity_load_avg(cfs_rq, se);
  	update_tg_load_avg(cfs_rq, false);
  	propagate_entity_cfs_rq(se);
  }
  
  static void attach_entity_cfs_rq(struct sched_entity *se)
  {
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  	/*
  	 * Since the real-depth could have been changed (only FAIR
  	 * class maintain depth value), reset depth properly.
  	 */
  	se->depth = se->parent ? se->parent->depth + 1 : 0;
  #endif
  
  	/* Synchronize entity with its cfs_rq */
  	update_load_avg(se, sched_feat(ATTACH_AGE_LOAD) ? 0 : SKIP_AGE_LOAD);
  	attach_entity_load_avg(cfs_rq, se);
  	update_tg_load_avg(cfs_rq, false);
  	propagate_entity_cfs_rq(se);
  }
  
  static void detach_task_cfs_rq(struct task_struct *p)
  {
  	struct sched_entity *se = &p->se;
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  
  	if (!vruntime_normalized(p)) {
  		/*
  		 * Fix up our vruntime so that the current sleep doesn't
  		 * cause 'unlimited' sleep bonus.
  		 */
  		place_entity(cfs_rq, se, 0);
  		se->vruntime -= cfs_rq->min_vruntime;
  	}
  
  	detach_entity_cfs_rq(se);
  }
  
  static void attach_task_cfs_rq(struct task_struct *p)
  {
  	struct sched_entity *se = &p->se;
  	struct cfs_rq *cfs_rq = cfs_rq_of(se);
  
  	attach_entity_cfs_rq(se);
  
  	if (!vruntime_normalized(p))
  		se->vruntime += cfs_rq->min_vruntime;
  }
  
  static void switched_from_fair(struct rq *rq, struct task_struct *p)
  {
  	detach_task_cfs_rq(p);
  }
  
  static void switched_to_fair(struct rq *rq, struct task_struct *p)
  {
  	attach_task_cfs_rq(p);
  
  	if (task_on_rq_queued(p)) {
  		/*
  		 * We were most likely switched from sched_rt, so
  		 * kick off the schedule if running, otherwise just see
  		 * if we can still preempt the current task.
  		 */
  		if (rq->curr == p)
  			resched_curr(rq);
  		else
  			check_preempt_curr(rq, p, 0);
  	}
  }
  
  /* Account for a task changing its policy or group.
   *
   * This routine is mostly called to set cfs_rq->curr field when a task
   * migrates between groups/classes.
   */
  static void set_curr_task_fair(struct rq *rq)
  {
  	struct sched_entity *se = &rq->curr->se;
  
  	for_each_sched_entity(se) {
  		struct cfs_rq *cfs_rq = cfs_rq_of(se);
  
  		set_next_entity(cfs_rq, se);
  		/* ensure bandwidth has been allocated on our new cfs_rq */
  		account_cfs_rq_runtime(cfs_rq, 0);
  	}
  }
  
  void init_cfs_rq(struct cfs_rq *cfs_rq)
  {
  	cfs_rq->tasks_timeline = RB_ROOT_CACHED;
  	cfs_rq->min_vruntime = (u64)(-(1LL << 20));
  #ifndef CONFIG_64BIT
  	cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
  #endif
  #ifdef CONFIG_SMP
  #ifdef CONFIG_FAIR_GROUP_SCHED
  	cfs_rq->propagate_avg = 0;
  #endif
  	atomic_long_set(&cfs_rq->removed_load_avg, 0);
  	atomic_long_set(&cfs_rq->removed_util_avg, 0);
  #endif
  }
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  static void task_set_group_fair(struct task_struct *p)
  {
  	struct sched_entity *se = &p->se;
  
  	set_task_rq(p, task_cpu(p));
  	se->depth = se->parent ? se->parent->depth + 1 : 0;
  }
  
  static void task_move_group_fair(struct task_struct *p)
  {
  	detach_task_cfs_rq(p);
  	set_task_rq(p, task_cpu(p));
  
  #ifdef CONFIG_SMP
  	/* Tell se's cfs_rq has been changed -- migrated */
  	p->se.avg.last_update_time = 0;
  #endif
  	attach_task_cfs_rq(p);
  }
  
  static void task_change_group_fair(struct task_struct *p, int type)
  {
  	switch (type) {
  	case TASK_SET_GROUP:
  		task_set_group_fair(p);
  		break;
  
  	case TASK_MOVE_GROUP:
  		task_move_group_fair(p);
  		break;
  	}
  }
  
  void free_fair_sched_group(struct task_group *tg)
  {
  	int i;
  
  	destroy_cfs_bandwidth(tg_cfs_bandwidth(tg));
  
  	for_each_possible_cpu(i) {
  		if (tg->cfs_rq)
  			kfree(tg->cfs_rq[i]);
  		if (tg->se)
  			kfree(tg->se[i]);
  	}
  
  	kfree(tg->cfs_rq);
  	kfree(tg->se);
  }
  
  int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
  {
  	struct sched_entity *se;
  	struct cfs_rq *cfs_rq;
  	int i;
  
  	tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL);
  	if (!tg->cfs_rq)
  		goto err;
  	tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL);
  	if (!tg->se)
  		goto err;
  
  	tg->shares = NICE_0_LOAD;
  
  	init_cfs_bandwidth(tg_cfs_bandwidth(tg));
  
  	for_each_possible_cpu(i) {
  		cfs_rq = kzalloc_node(sizeof(struct cfs_rq),
  				      GFP_KERNEL, cpu_to_node(i));
  		if (!cfs_rq)
  			goto err;
  
  		se = kzalloc_node(sizeof(struct sched_entity),
  				  GFP_KERNEL, cpu_to_node(i));
  		if (!se)
  			goto err_free_rq;
  
  		init_cfs_rq(cfs_rq);
  		init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]);
  		init_entity_runnable_average(se);
  	}
  
  	return 1;
  
  err_free_rq:
  	kfree(cfs_rq);
  err:
  	return 0;
  }
  
  void online_fair_sched_group(struct task_group *tg)
  {
  	struct sched_entity *se;
  	struct rq_flags rf;
  	struct rq *rq;
  	int i;
  
  	for_each_possible_cpu(i) {
  		rq = cpu_rq(i);
  		se = tg->se[i];
  		rq_lock_irq(rq, &rf);
  		update_rq_clock(rq);
  		attach_entity_cfs_rq(se);
  		sync_throttle(tg, i);
  		rq_unlock_irq(rq, &rf);
  	}
  }
  
  void unregister_fair_sched_group(struct task_group *tg)
  {
  	unsigned long flags;
  	struct rq *rq;
  	int cpu;
  
  	for_each_possible_cpu(cpu) {
  		if (tg->se[cpu])
  			remove_entity_load_avg(tg->se[cpu]);
  
  		/*
  		 * Only empty task groups can be destroyed; so we can speculatively
  		 * check on_list without danger of it being re-added.
  		 */
  		if (!tg->cfs_rq[cpu]->on_list)
  			continue;
  
  		rq = cpu_rq(cpu);
  
  		raw_spin_lock_irqsave(&rq->lock, flags);
  		list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
  		raw_spin_unlock_irqrestore(&rq->lock, flags);
  	}
  }
  
  void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
  			struct sched_entity *se, int cpu,
  			struct sched_entity *parent)
  {
  	struct rq *rq = cpu_rq(cpu);
  
  	cfs_rq->tg = tg;
  	cfs_rq->rq = rq;
  	init_cfs_rq_runtime(cfs_rq);
  
  	tg->cfs_rq[cpu] = cfs_rq;
  	tg->se[cpu] = se;
  
  	/* se could be NULL for root_task_group */
  	if (!se)
  		return;
  
  	if (!parent) {
  		se->cfs_rq = &rq->cfs;
  		se->depth = 0;
  	} else {
  		se->cfs_rq = parent->my_q;
  		se->depth = parent->depth + 1;
  	}
  
  	se->my_q = cfs_rq;
  	/* guarantee group entities always have weight */
  	update_load_set(&se->load, NICE_0_LOAD);
  	se->parent = parent;
  }
  
  static DEFINE_MUTEX(shares_mutex);
  
  int sched_group_set_shares(struct task_group *tg, unsigned long shares)
  {
  	int i;
  
  	/*
  	 * We can't change the weight of the root cgroup.
  	 */
  	if (!tg->se[0])
  		return -EINVAL;
  
  	shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES));
  
  	mutex_lock(&shares_mutex);
  	if (tg->shares == shares)
  		goto done;
  
  	tg->shares = shares;
  	for_each_possible_cpu(i) {
  		struct rq *rq = cpu_rq(i);
  		struct sched_entity *se = tg->se[i];
  		struct rq_flags rf;
  
  		/* Propagate contribution to hierarchy */
  		rq_lock_irqsave(rq, &rf);
  		update_rq_clock(rq);
  		for_each_sched_entity(se) {
  			update_load_avg(se, UPDATE_TG);
  			update_cfs_shares(se);
  		}
  		rq_unlock_irqrestore(rq, &rf);
  	}
  
  done:
  	mutex_unlock(&shares_mutex);
  	return 0;
  }
  #else /* CONFIG_FAIR_GROUP_SCHED */
  
  void free_fair_sched_group(struct task_group *tg) { }
  
  int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
  {
  	return 1;
  }
  
  void online_fair_sched_group(struct task_group *tg) { }
  
  void unregister_fair_sched_group(struct task_group *tg) { }
  
  #endif /* CONFIG_FAIR_GROUP_SCHED */
  
  
  static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task)
  {
  	struct sched_entity *se = &task->se;
  	unsigned int rr_interval = 0;
  
  	/*
  	 * Time slice is 0 for SCHED_OTHER tasks that are on an otherwise
  	 * idle runqueue:
  	 */
  	if (rq->cfs.load.weight)
  		rr_interval = NS_TO_JIFFIES(sched_slice(cfs_rq_of(se), se));
  
  	return rr_interval;
  }
  
  /*
   * All the scheduling class methods:
   */
  const struct sched_class fair_sched_class = {
  	.next			= &idle_sched_class,
  	.enqueue_task		= enqueue_task_fair,
  	.dequeue_task		= dequeue_task_fair,
  	.yield_task		= yield_task_fair,
  	.yield_to_task		= yield_to_task_fair,
  
  	.check_preempt_curr	= check_preempt_wakeup,
  
  	.pick_next_task		= pick_next_task_fair,
  	.put_prev_task		= put_prev_task_fair,
  
  #ifdef CONFIG_SMP
  	.select_task_rq		= select_task_rq_fair,
  	.migrate_task_rq	= migrate_task_rq_fair,
  
  	.rq_online		= rq_online_fair,
  	.rq_offline		= rq_offline_fair,
  
  	.task_dead		= task_dead_fair,
  	.set_cpus_allowed	= set_cpus_allowed_common,
  #endif
  
  	.set_curr_task          = set_curr_task_fair,
  	.task_tick		= task_tick_fair,
  	.task_fork		= task_fork_fair,
  
  	.prio_changed		= prio_changed_fair,
  	.switched_from		= switched_from_fair,
  	.switched_to		= switched_to_fair,
  
  	.get_rr_interval	= get_rr_interval_fair,
  
  	.update_curr		= update_curr_fair,
  
  #ifdef CONFIG_FAIR_GROUP_SCHED
  	.task_change_group	= task_change_group_fair,
  #endif
  #ifdef CONFIG_SCHED_WALT
  	.fixup_cumulative_runnable_avg =
  		walt_fixup_cumulative_runnable_avg_fair,
  #endif
  };
  
  #ifdef CONFIG_SCHED_DEBUG
  void print_cfs_stats(struct seq_file *m, int cpu)
  {
  	struct cfs_rq *cfs_rq;
  
  	rcu_read_lock();
  	for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq)
  		print_cfs_rq(m, cpu, cfs_rq);
  	rcu_read_unlock();
  }
  
  #ifdef CONFIG_NUMA_BALANCING
  void show_numa_stats(struct task_struct *p, struct seq_file *m)
  {
  	int node;
  	unsigned long tsf = 0, tpf = 0, gsf = 0, gpf = 0;
  
  	for_each_online_node(node) {
  		if (p->numa_faults) {
  			tsf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 0)];
  			tpf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 1)];
  		}
  		if (p->numa_group) {
  			gsf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 0)],
  			gpf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 1)];
  		}
  		print_numa_stats(m, node, tsf, tpf, gsf, gpf);
  	}
  }
  #endif /* CONFIG_NUMA_BALANCING */
  #endif /* CONFIG_SCHED_DEBUG */
  
  __init void init_sched_fair_class(void)
  {
  #ifdef CONFIG_SMP
  	open_softirq(SCHED_SOFTIRQ, run_rebalance_domains);
  
  #ifdef CONFIG_NO_HZ_COMMON
  	nohz.next_balance = jiffies;
  	nohz.next_update = jiffies;
  	zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT);
  #endif
  
  	alloc_eenv();
  #endif /* SMP */
  
  }
  
  #ifdef CONFIG_HISI_EAS_SCHED
  #define EAS_DATA_SYSFS_MAX	10
  
  struct eas_global_attr {
  	struct attribute attr;
  	ssize_t (*show)(struct kobject *kobj,
  			struct kobj_attribute *kattr, char *buf);
  	ssize_t (*store)(struct kobject *kobj, struct kobj_attribute *kattr,
  			const char *buf, size_t count);
  	int *value;
  };
  
  struct eas_data_struct {
  	struct attribute_group attr_group;
  	struct attribute *attributes[EAS_DATA_SYSFS_MAX + 1];
  	struct eas_global_attr attr[EAS_DATA_SYSFS_MAX];
  } eas_data;
  
  static ssize_t eas_show(struct kobject *kobj,
  				struct kobj_attribute *kattr, char *buf)
  {
  	struct eas_global_attr *eas_attr =
  		container_of(&kattr->attr, struct eas_global_attr, attr);
  	int temp;
  
  	temp = *(eas_attr->value);
  	return (ssize_t)sprintf(buf, "%d\n", temp);
  }
  
  static ssize_t eas_store(struct kobject *kobj, struct kobj_attribute *kattr,
  				const char *buf, size_t count)
  {
  	int temp;
  	ssize_t ret = count;
  	struct eas_global_attr *eas_attr =
  		container_of(&kattr->attr, struct eas_global_attr, attr);
  	char *str = vmalloc(count + 1);
  
  	if (str == NULL)
  		return -ENOMEM;
  
  	memcpy(str, buf, count);
  	str[count] = 0;
  	if (sscanf(str, "%d", &temp) < 1)
  		ret = -EINVAL;
  	else {
  		if (temp < 0)
  			ret = -EINVAL;
  		else
  			*(eas_attr->value) = temp;
  	}
  
  	/* trace the name and value of the attribute */
  	trace_eas_attr_store(kattr->attr.name, temp);
  	vfree(str);
  	return ret;
  }
  
  #ifdef CONFIG_HISI_MULTI_MARGIN
  static unsigned int *get_tokenized_data(const char *buf)
  {
  	const char *cp;
  	int i;
  	int ntokens = 1;
  	unsigned int *tokenized_data;
  	int err = -EINVAL;
  
  	cp = buf;
  	while ((cp = strpbrk(cp + 1, " :")))
  		ntokens++;
  
  	if (ntokens != num_clusters)
  		goto err;
  
  	tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
  	if (!tokenized_data) {
  		err = -ENOMEM;
  		goto err;
  	}
  
  	cp = buf;
  	i = 0;
  	while (i < ntokens) {
  		if (sscanf(cp, "%u", &tokenized_data[i++]) != 1) /* [false alarm]:fortify */
  			goto err_kfree;
  
  		cp = strpbrk(cp, " :");
  		if (!cp)
  			break;
  		cp++;
  	}
  
  	if (i != ntokens)
  		goto err_kfree;
  
  	return tokenized_data;
  
  err_kfree:
  	kfree(tokenized_data);
  err:
  	return ERR_PTR(err);
  }
  
  static ssize_t capacity_margin_show(struct kobject *kobj,
  				struct kobj_attribute *kattr, char *buf)
  {
  	struct sched_cluster *cluster;
  	ssize_t ret = 0;
  
  	for_each_sched_cluster(cluster) {
  		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u%s",
  				cluster->capacity_margin, ":");
  	}
  
  	sprintf(buf + ret - 1, "\n"); /*lint !e421*/
  	return ret;
  }
  
  static ssize_t sd_capacity_margin_show(struct kobject *kobj,
  				struct kobj_attribute *kattr, char *buf)
  {
  	struct sched_cluster *cluster;
  	ssize_t ret = 0;
  
  	for_each_sched_cluster(cluster) {
  		ret += scnprintf(buf + ret, PAGE_SIZE - ret, "%u%s",
  				cluster->sd_capacity_margin, ":");
  	}
  
  	sprintf(buf + ret - 1, "\n"); /*lint !e421*/
  	return ret;
  }
  
  static ssize_t capacity_margin_store(struct kobject *kobj, struct kobj_attribute *kattr,
  				const char *buf, size_t count)
  {
  	char *str;
  	unsigned int *new_margin;
  	struct sched_cluster *cluster;
  	int i;
  
  	str = vmalloc(count + 1);
  	if (str == NULL)
  		return -ENOMEM;
  	memcpy(str, buf, count);
  	str[count] = 0;
  
  	new_margin = get_tokenized_data(str);
  
  	vfree(str);
  
  	if (IS_ERR(new_margin))
  		return PTR_ERR(new_margin);
  
  	i = 0;
  	for_each_sched_cluster(cluster) {
  		cluster->capacity_margin = new_margin[i++];
  	}
  
  	kfree(new_margin);
  	return count;
  }
  
  static ssize_t sd_capacity_margin_store(struct kobject *kobj, struct kobj_attribute *kattr,
  				const char *buf, size_t count)
  {
  	char *str;
  	unsigned int *new_margin;
  	struct sched_cluster *cluster;
  	int i;
  
  	str = vmalloc(count + 1);
  	if (str == NULL)
  		return -ENOMEM;
  	memcpy(str, buf, count);
  	str[count] = 0;
  
  	new_margin = get_tokenized_data(str);
  
  	vfree(str);
  
  	if (IS_ERR(new_margin))
  		return PTR_ERR(new_margin);
  
  	i = 0;
  	for_each_sched_cluster(cluster) {
  		cluster->sd_capacity_margin = new_margin[i++];
  	}
  
  	kfree(new_margin);
  	return count;
  }
  #endif /* CONFIG_HISI_MULTI_MARGIN */
  
  #ifdef CONFIG_SCHED_HISI_PRED_LOAD
  static ssize_t predl_window_size_show(struct kobject *kobj,
  			struct kobj_attribute *kattr, char *buf)
  {
  	return scnprintf(buf, PAGE_SIZE, "%u\n", predl_window_size);
  }
  
  #define MIN_PREDL_WINDOW_SIZE 4000000 /* 4ms */
  #define MAX_PREDL_WINDOW_SIZE 32000000 /* 32ms */
  static ssize_t predl_window_size_store(struct kobject *kobj,
  		struct kobj_attribute *kattr, const char *buf, size_t count)
  {
  	unsigned int val;
  
  	if (kstrtouint(buf, 10, &val))
  		return -EINVAL;
  
  	if (val < MIN_PREDL_WINDOW_SIZE ||
  	    val > MAX_PREDL_WINDOW_SIZE)
  		return -EINVAL;
  
  	predl_window_size = val;
  
  	return count;
  }
  #endif
  
  static void eas_attr_add(
  	const char *name,
  	int *value,
  	ssize_t (*show)(struct kobject *,
  			struct kobj_attribute *, char *),
  	ssize_t (*store)(struct kobject *, struct kobj_attribute *,
  			const char *, size_t),
  	umode_t mode)
  {
  	int i = 0;
  
  	while (eas_data.attributes[i] != NULL) {
  		i++;
  		if (i >= EAS_DATA_SYSFS_MAX)
  			return;
  	}
  
  	if (mode)
  		eas_data.attr[i].attr.mode = mode;
  	else
  		eas_data.attr[i].attr.mode = 0640;
  	if (show)
  		eas_data.attr[i].show = show;
  	else
  		eas_data.attr[i].show = eas_show;
  	if (store)
  		eas_data.attr[i].store = store;
  	else
  		eas_data.attr[i].store = eas_store;
  
  	eas_data.attr[i].attr.name = name;
  	eas_data.attr[i].value = value;
  	eas_data.attributes[i] = &eas_data.attr[i].attr;
  	eas_data.attributes[i + 1] = NULL;
  }
  
  /*
   * Note:
   * 1. Do not forget to increase array size EAS_DATA_SYSFS_MAX when
   * adding a new attribute.
   * 2. The second parameter of eas_attr_add will be transformed to
   * pointer to int, so don't pass type shorter than int.
   */
  static int eas_attr_init(void)
  {
  	int ret;
  
  	memset(&eas_data, 0, sizeof(eas_data));
  
  	eas_attr_add("boost",
  		&global_boost_enable,
  		NULL,
  		NULL,
  		0640);
  
  	eas_attr_add("up_migration_util_filter",
  		&up_migration_util_filter,
  		NULL,
  		NULL,
  		0640);
  
  #ifndef CONFIG_HISI_MULTI_MARGIN
  	eas_attr_add("sd_capacity_margin",
  		&sd_capacity_margin,
  		NULL,
  		NULL,
  		0640);
  
  	eas_attr_add("capacity_margin",
  		&capacity_margin,
  		NULL,
  		NULL,
  		0640);
  #else
  	eas_attr_add("sd_capacity_margin",
  		NULL,
  		sd_capacity_margin_show,
  		sd_capacity_margin_store,
  		0640);
  
  	eas_attr_add("capacity_margin",
  		NULL,
  		capacity_margin_show,
  		capacity_margin_store,
  		0640);
  #endif
  
  	eas_attr_add("boot_boost",
  		&boot_boost,
  		NULL,
  		NULL,
  		0640);
  
  	eas_attr_add("task_boost_limit",
  		&task_boost_limit,
  		NULL,
  		NULL,
  		0640);
  
  #ifdef CONFIG_SCHED_HISI_PRED_LOAD
  	eas_attr_add("predl_enable",
  		&predl_enable,
  		NULL,
  		NULL,
  		0640);
  
  	eas_attr_add("predl_jump_load",
  		&predl_jump_load,
  		NULL,
  		NULL,
  		0640);
  
  	eas_attr_add("predl_do_predict",
  		&predl_do_predict,
  		NULL,
  		NULL,
  		0640);
  
  	eas_attr_add("predl_window_size",
  		NULL,
  		predl_window_size_show,
  		predl_window_size_store,
  		0640);
  #endif
  
  	eas_data.attr_group.name = "eas";
  	eas_data.attr_group.attrs = eas_data.attributes;
  	ret = sysfs_create_group(kernel_kobj,
  		&eas_data.attr_group);
  
  	return 0;
  }
  late_initcall(eas_attr_init);
  #endif
  