include/linux/delayacct.h

   1 /* delayacct.h - per-task delay accounting
   2  *
   3  * Copyright (C) Shailabh Nagar, IBM Corp. 2006
   4  *
   5  * This program is free software;  you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  13  * the GNU General Public License for more details.
  14  *
  15  */
  16
  17 #ifndef _LINUX_DELAYACCT_H
  18 #define _LINUX_DELAYACCT_H
  19
  20 #include <linux/sched.h>
  21
  22 /*
  23  * Per-task flags relevant to delay accounting
  24  * maintained privately to avoid exhausting similar flags in sched.h:PF_*
  25  * Used to set current->delays->flags
  26  */
  27 #define DELAYACCT_PF_SWAPIN     0x00000001      /* I am doing a swapin */
  28
  29 #ifdef CONFIG_TASK_DELAY_ACCT
  30
  31 extern int delayacct_on;        /* Delay accounting turned on/off */
  32 extern kmem_cache_t *delayacct_cache;
  33 extern void delayacct_init(void);
  34 extern void __delayacct_tsk_init(struct task_struct *);
  35 extern void __delayacct_tsk_exit(struct task_struct *);
  36 extern void __delayacct_blkio_start(void);
  37 extern void __delayacct_blkio_end(void);
  38
  39 static inline void delayacct_set_flag(int flag)
  40 {
  41         if (current->delays)
  42                 current->delays->flags |= flag;
  43 }
  44
  45 static inline void delayacct_clear_flag(int flag)
  46 {
  47         if (current->delays)
  48                 current->delays->flags &= ~flag;
  49 }
  50
  51 static inline void delayacct_tsk_init(struct task_struct *tsk)
  52 {
  53         /* reinitialize in case parent's non-null pointer was dup'ed*/
  54         tsk->delays = NULL;
  55         if (unlikely(delayacct_on))
  56                 __delayacct_tsk_init(tsk);
  57 }
  58
  59 static inline void delayacct_tsk_exit(struct task_struct *tsk)
  60 {
  61         if (tsk->delays)
  62                 __delayacct_tsk_exit(tsk);
  63 }
  64
  65 static inline void delayacct_blkio_start(void)
  66 {
  67         if (current->delays)
  68                 __delayacct_blkio_start();
  69 }
  70
  71 static inline void delayacct_blkio_end(void)
  72 {
  73         if (current->delays)
  74                 __delayacct_blkio_end();
  75 }
  76
  77 #else
  78 static inline void delayacct_set_flag(int flag)
  79 {}
  80 static inline void delayacct_clear_flag(int flag)
  81 {}
  82 static inline void delayacct_init(void)
  83 {}
  84 static inline void delayacct_tsk_init(struct task_struct *tsk)
  85 {}
  86 static inline void delayacct_tsk_exit(struct task_struct *tsk)
  87 {}
  88 static inline void delayacct_blkio_start(void)
  89 {}
  90 static inline void delayacct_blkio_end(void)
  91 {}
  92 #endif /* CONFIG_TASK_DELAY_ACCT */
  93
  94 #endif