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
  10 struct 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 DEFINE_RATELIMIT_STATE(name, interval_init, burst_init)         \
  21                                                                         \
  22         struct ratelimit_state name = {                                 \
  23                 .lock           = __RAW_SPIN_LOCK_UNLOCKED(name.lock),  \
  24                 .interval       = interval_init,                        \
  25                 .burst          = burst_init,                           \
  26         }
  27
  28 static inline void ratelimit_state_init(struct ratelimit_state *rs,
  29                                         int interval, int burst)
  30 {
  31         raw_spin_lock_init(&rs->lock);
  32         rs->interval = interval;
  33         rs->burst = burst;
  34         rs->printed = 0;
  35         rs->missed = 0;
  36         rs->begin = 0;
  37 }
  38
  39 extern struct ratelimit_state printk_ratelimit_state;
  40
  41 extern int ___ratelimit(struct ratelimit_state *rs, const char *func);
  42 #define __ratelimit(state) ___ratelimit(state, __func__)
  43
  44 #ifdef CONFIG_PRINTK
  45
  46 #define WARN_ON_RATELIMIT(condition, state)                     \
  47                 WARN_ON((condition) && __ratelimit(state))
  48
  49 #define WARN_RATELIMIT(condition, format, ...)                  \
  50 ({                                                              \
  51         static DEFINE_RATELIMIT_STATE(_rs,                      \
  52                                       DEFAULT_RATELIMIT_INTERVAL,       \
  53                                       DEFAULT_RATELIMIT_BURST); \
  54         int rtn = !!(condition);                                \
  55                                                                 \
  56         if (unlikely(rtn && __ratelimit(&_rs)))                 \
  57                 WARN(rtn, format, ##__VA_ARGS__);               \
  58                                                                 \
  59         rtn;                                                    \
  60 })
  61
  62 #else
  63
  64 #define WARN_ON_RATELIMIT(condition, state)                     \
  65         WARN_ON(condition)
  66
  67 #define WARN_RATELIMIT(condition, format, ...)                  \
  68 ({                                                              \
  69         int rtn = WARN(condition, format, ##__VA_ARGS__);       \
  70         rtn;                                                    \
  71 })
  72
  73 #endif
  74
  75 #endif /* _LINUX_RATELIMIT_H */