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 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
  34 static 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
  45 extern struct ratelimit_state printk_ratelimit_state;
  46
  47 extern 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 */