LXR linux/include/linux/ratelimit.h

   1#ifndef _LINUX_RATELIMIT_H
   2#define _LINUX_RATELIMIT_H
   3
   4#include <linux/param.h>
   5#include <linux/spinlock.h>
   6
   7#define DEFAULT_RATELIMIT_INTERVAL      (5 * HZ)
   8#define DEFAULT_RATELIMIT_BURST         10
   9
  10struct ratelimit_state {
  11        raw_spinlock_t  lock;           /* protect the state */
  12
  13        int             interval;
  14        int             burst;
  15        int             printed;
  16        int             missed;
  17        unsigned long   begin;
  18};
  19
  20#define RATELIMIT_STATE_INIT(name, interval_init, burst_init) {         \
  21                .lock           = __RAW_SPIN_LOCK_UNLOCKED(name.lock),  \
  22                .interval       = interval_init,                        \
  23                .burst          = burst_init,                           \
  24        }
  25
  26#define RATELIMIT_STATE_INIT_DISABLED                                   \
  27        RATELIMIT_STATE_INIT(ratelimit_state, 0, DEFAULT_RATELIMIT_BURST)
  28
  29#define DEFINE_RATELIMIT_STATE(name, interval_init, burst_init)         \
  30                                                                        \
  31        struct ratelimit_state name =                                   \
  32                RATELIMIT_STATE_INIT(name, interval_init, burst_init)   \
  33
  34static inline void ratelimit_state_init(struct ratelimit_state *rs,
  35                                        int interval, int burst)
  36{
  37        raw_spin_lock_init(&rs->lock);
  38        rs->interval = interval;
  39        rs->burst = burst;
  40        rs->printed = 0;
  41        rs->missed = 0;
  42        rs->begin = 0;
  43}
  44
  45extern struct ratelimit_state printk_ratelimit_state;
  46
  47extern int ___ratelimit(struct ratelimit_state *rs, const char *func);
  48#define __ratelimit(state) ___ratelimit(state, __func__)
  49
  50#ifdef CONFIG_PRINTK
  51
  52#define WARN_ON_RATELIMIT(condition, state)                     \
  53                WARN_ON((condition) && __ratelimit(state))
  54
  55#define WARN_RATELIMIT(condition, format, ...)                  \
  56({                                                              \
  57        static DEFINE_RATELIMIT_STATE(_rs,                      \
  58                                      DEFAULT_RATELIMIT_INTERVAL,       \
  59                                      DEFAULT_RATELIMIT_BURST); \
  60        int rtn = !!(condition);                                \
  61                                                                \
  62        if (unlikely(rtn && __ratelimit(&_rs)))                 \
  63                WARN(rtn, format, ##__VA_ARGS__);               \
  64                                                                \
  65        rtn;                                                    \
  66})
  67
  68#else
  69
  70#define WARN_ON_RATELIMIT(condition, state)                     \
  71        WARN_ON(condition)
  72
  73#define WARN_RATELIMIT(condition, format, ...)                  \
  74({                                                              \
  75        int rtn = WARN(condition, format, ##__VA_ARGS__);       \
  76        rtn;                                                    \
  77})
  78
  79#endif
  80
  81#endif /* _LINUX_RATELIMIT_H */
  82