text: #ifndef _LINUX_RATELIMIT_H
  #define _LINUX_RATELIMIT_H
  
  #include <linux/param.h>
  #include <linux/spinlock_types.h>
  
  #define DEFAULT_RATELIMIT_INTERVAL	(5 * HZ)
  #define DEFAULT_RATELIMIT_BURST		10
  
  struct ratelimit_state {
  	spinlock_t	lock;		/* protect the state */
  
  	int		interval;
  	int		burst;
  	int		printed;
  	int		missed;
  	unsigned long	begin;
  };
  
  #define DEFINE_RATELIMIT_STATE(name, interval_init, burst_init)		\
  									\
  	struct ratelimit_state name = {					\
  		.lock		= __SPIN_LOCK_UNLOCKED(name.lock),	\
  		.interval	= interval_init,			\
  		.burst		= burst_init,				\
  	}
  
  extern int ___ratelimit(struct ratelimit_state *rs, const char *func);
  #define __ratelimit(state) ___ratelimit(state, __func__)
  
  #endif /* _LINUX_RATELIMIT_H */
  