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         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           = __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         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, state, format...)           \
  50 ({                                                              \
  51         int rtn = 0;                                            \
  52         if (unlikely(__ratelimit(state)))                       \
  53                 rtn = WARN(condition, format);                  \
  54         rtn;                                                    \
  55 })
  56
  57 #define WARN_RATELIMIT(condition, format...)                    \
  58 ({                                                              \
  59         static DEFINE_RATELIMIT_STATE(_rs,                      \
  60                                       DEFAULT_RATELIMIT_INTERVAL,       \
  61                                       DEFAULT_RATELIMIT_BURST); \
  62         __WARN_RATELIMIT(condition, &_rs, format);              \
  63 })
  64
  65 #else
  66
  67 #define WARN_ON_RATELIMIT(condition, state)                     \
  68         WARN_ON(condition)
  69
  70 #define __WARN_RATELIMIT(condition, state, format...)           \
  71 ({                                                              \
  72         int rtn = WARN(condition, format);                      \
  73         rtn;                                                    \
  74 })
  75
  76 #define WARN_RATELIMIT(condition, format...)                    \
  77 ({                                                              \
  78         int rtn = WARN(condition, format);                      \
  79         rtn;                                                    \
  80 })
  81
  82 #endif
  83
  84 #endif /* _LINUX_RATELIMIT_H */