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 struct task_struct;
  14
  15 #ifdef CONFIG_LATENCYTOP
  16
  17 #define LT_SAVECOUNT            32
  18 #define LT_BACKTRACEDEPTH       12
  19
  20 struct latency_record {
  21         unsigned long   backtrace[LT_BACKTRACEDEPTH];
  22         unsigned int    count;
  23         unsigned long   time;
  24         unsigned long   max;
  25 };
  26
  27
  28
  29 extern int latencytop_enabled;
  30 void __account_scheduler_latency(struct task_struct *task, int usecs, int inter);
  31 static inline void
  32 account_scheduler_latency(struct task_struct *task, int usecs, int inter)
  33 {
  34         if (unlikely(latencytop_enabled))
  35                 __account_scheduler_latency(task, usecs, inter);
  36 }
  37
  38 void clear_all_latency_tracing(struct task_struct *p);
  39
  40 extern int sysctl_latencytop(struct ctl_table *table, int write,
  41                         void __user *buffer, size_t *lenp, loff_t *ppos);
  42
  43 #else
  44
  45 static inline void
  46 account_scheduler_latency(struct task_struct *task, int usecs, int inter)
  47 {
  48 }
  49
  50 static inline void clear_all_latency_tracing(struct task_struct *p)
  51 {
  52 }
  53
  54 #endif
  55
  56 #endif