include/linux/latencytop.h

   1 /*
   2  * latencytop.h: Infrastructure for displaying latency
   3  *
   4  * (C) Copyright 2008 Intel Corporation
   5  * Author: Arjan van de Ven <arjan@linux.intel.com>
   6  *
   7  */
   8
   9 #ifndef _INCLUDE_GUARD_LATENCYTOP_H_
  10 #define _INCLUDE_GUARD_LATENCYTOP_H_
  11
  12 #include <linux/compiler.h>
  13 #ifdef CONFIG_LATENCYTOP
  14
  15 #define LT_SAVECOUNT            32
  16 #define LT_BACKTRACEDEPTH       12
  17
  18 struct latency_record {
  19         unsigned long   backtrace[LT_BACKTRACEDEPTH];
  20         unsigned int    count;
  21         unsigned long   time;
  22         unsigned long   max;
  23 };
  24
  25
  26 struct task_struct;
  27
  28 extern int latencytop_enabled;
  29 void __account_scheduler_latency(struct task_struct *task, int usecs, int inter);
  30 static inline void
  31 account_scheduler_latency(struct task_struct *task, int usecs, int inter)
  32 {
  33         if (unlikely(latencytop_enabled))
  34                 __account_scheduler_latency(task, usecs, inter);
  35 }
  36
  37 void clear_all_latency_tracing(struct task_struct *p);
  38
  39 #else
  40
  41 static inline void
  42 account_scheduler_latency(struct task_struct *task, int usecs, int inter)
  43 {
  44 }
  45
  46 static inline void clear_all_latency_tracing(struct task_struct *p)
  47 {
  48 }
  49
  50 #endif
  51
  52 #endif