text: /* SPDX-License-Identifier: GPL-2.0 */
  #ifndef LINUX_MM_INLINE_H
  #define LINUX_MM_INLINE_H
  
  #include <linux/huge_mm.h>
  #include <linux/swap.h>
  
  /**
   * page_is_file_lru - should the page be on a file LRU or anon LRU?
   * @page: the page to test
   *
   * Returns 1 if @page is a regular filesystem backed page cache page or a lazily
   * freed anonymous page (e.g. via MADV_FREE).  Returns 0 if @page is a normal
   * anonymous page, a tmpfs page or otherwise ram or swap backed page.  Used by
   * functions that manipulate the LRU lists, to sort a page onto the right LRU
   * list.
   *
   * We would like to get this info without a page flag, but the state
   * needs to survive until the page is last deleted from the LRU, which
   * could be as far down as __page_cache_release.
   */
  static inline int page_is_file_lru(struct page *page)
  {
  	return !PageSwapBacked(page);
  }
  
  static __always_inline void update_lru_size(struct lruvec *lruvec,
  				enum lru_list lru, enum zone_type zid,
  				int nr_pages)
  {
  	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
  
  	__mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
  	__mod_zone_page_state(&pgdat->node_zones[zid],
  				NR_ZONE_LRU_BASE + lru, nr_pages);
  #ifdef CONFIG_MEMCG
  	mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages);
  #endif
  }
  
  /**
   * __clear_page_lru_flags - clear page lru flags before releasing a page
   * @page: the page that was on lru and now has a zero reference
   */
  static __always_inline void __clear_page_lru_flags(struct page *page)
  {
  	VM_BUG_ON_PAGE(!PageLRU(page), page);
  
  	__ClearPageLRU(page);
  
  	/* this shouldn't happen, so leave the flags to bad_page() */
  	if (PageActive(page) && PageUnevictable(page))
  		return;
  
  	__ClearPageActive(page);
  	__ClearPageUnevictable(page);
  }
  
  /**
   * page_lru - which LRU list should a page be on?
   * @page: the page to test
   *
   * Returns the LRU list a page should be on, as an index
   * into the array of LRU lists.
   */
  static __always_inline enum lru_list page_lru(struct page *page)
  {
  	enum lru_list lru;
  
  	VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page);
  
  	if (PageUnevictable(page))
  		return LRU_UNEVICTABLE;
  
  	lru = page_is_file_lru(page) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
  	if (PageActive(page))
  		lru += LRU_ACTIVE;
  
  	return lru;
  }
  
  static __always_inline void add_page_to_lru_list(struct page *page,
  				struct lruvec *lruvec)
  {
  	enum lru_list lru = page_lru(page);
  
  	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
  	list_add(&page->lru, &lruvec->lists[lru]);
  }
  
  static __always_inline void add_page_to_lru_list_tail(struct page *page,
  				struct lruvec *lruvec)
  {
  	enum lru_list lru = page_lru(page);
  
  	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
  	list_add_tail(&page->lru, &lruvec->lists[lru]);
  }
  
  static __always_inline void del_page_from_lru_list(struct page *page,
  				struct lruvec *lruvec)
  {
  	list_del(&page->lru);
  	update_lru_size(lruvec, page_lru(page), page_zonenum(page),
  			-thp_nr_pages(page));
  }
  #endif
  