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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#include <linux/taskstats_kern.h>
22
23/*
24 * Per-task flags relevant to delay accounting
25 * maintained privately to avoid exhausting similar flags in sched.h:PF_*
26 * Used to set current->delays->flags
27 */
28#define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */
29
30#ifdef CONFIG_TASK_DELAY_ACCT
31
32extern int delayacct_on; /* Delay accounting turned on/off */
33extern kmem_cache_t *delayacct_cache;
34extern void delayacct_init(void);
35extern void __delayacct_tsk_init(struct task_struct *);
36extern void __delayacct_tsk_exit(struct task_struct *);
37extern void __delayacct_blkio_start(void);
38extern void __delayacct_blkio_end(void);
39extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
40extern __u64 __delayacct_blkio_ticks(struct task_struct *);
41
42static inline void delayacct_set_flag(int flag)
43{
44 if (current->delays)
45 current->delays->flags |= flag;
46}
47
48static inline void delayacct_clear_flag(int flag)
49{
50 if (current->delays)
51 current->delays->flags &= ~flag;
52}
53
54static inline void delayacct_tsk_init(struct task_struct *tsk)
55{
56 /* reinitialize in case parent's non-null pointer was dup'ed*/
57 tsk->delays = NULL;
58 if (unlikely(delayacct_on))
59 __delayacct_tsk_init(tsk);
60}
61
62static inline void delayacct_tsk_exit(struct task_struct *tsk)
63{
64 if (tsk->delays)
65 __delayacct_tsk_exit(tsk);
66}
67
68static inline void delayacct_blkio_start(void)
69{
70 if (current->delays)
71 __delayacct_blkio_start();
72}
73
74static inline void delayacct_blkio_end(void)
75{
76 if (current->delays)
77 __delayacct_blkio_end();
78}
79
80static inline int delayacct_add_tsk(struct taskstats *d,
81 struct task_struct *tsk)
82{
83 if (likely(!delayacct_on))
84 return -EINVAL;
85 if (!tsk->delays)
86 return 0;
87 return __delayacct_add_tsk(d, tsk);
88}
89
90static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
91{
92 if (tsk->delays)
93 return __delayacct_blkio_ticks(tsk);
94 return 0;
95}
96
97#else
98static inline void delayacct_set_flag(int flag)
99{}
100static inline void delayacct_clear_flag(int flag)
101{}
102static inline void delayacct_init(void)
103{}
104static inline void delayacct_tsk_init(struct task_struct *tsk)
105{}
106static inline void delayacct_tsk_exit(struct task_struct *tsk)
107{}
108static inline void delayacct_blkio_start(void)
109{}
110static inline void delayacct_blkio_end(void)
111{}
112static inline int delayacct_add_tsk(struct taskstats *d,
113 struct task_struct *tsk)
114{ return 0; }
115static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
116{ return 0; }
117#endif /* CONFIG_TASK_DELAY_ACCT */
118
119#endif