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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 (delayacct_on)
59 __delayacct_tsk_init(tsk);
60}
61
62/* Free tsk->delays. Called from bad fork and __put_task_struct
63 * where there's no risk of tsk->delays being accessed elsewhere
64 */
65static inline void delayacct_tsk_free(struct task_struct *tsk)
66{
67 if (tsk->delays)
68 kmem_cache_free(delayacct_cache, tsk->delays);
69 tsk->delays = NULL;
70}
71
72static inline void delayacct_blkio_start(void)
73{
74 if (current->delays)
75 __delayacct_blkio_start();
76}
77
78static inline void delayacct_blkio_end(void)
79{
80 if (current->delays)
81 __delayacct_blkio_end();
82}
83
84static inline int delayacct_add_tsk(struct taskstats *d,
85 struct task_struct *tsk)
86{
87 if (!delayacct_on || !tsk->delays)
88 return 0;
89 return __delayacct_add_tsk(d, tsk);
90}
91
92static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
93{
94 if (tsk->delays)
95 return __delayacct_blkio_ticks(tsk);
96 return 0;
97}
98
99#else
100static inline void delayacct_set_flag(int flag)
101{}
102static inline void delayacct_clear_flag(int flag)
103{}
104static inline void delayacct_init(void)
105{}
106static inline void delayacct_tsk_init(struct task_struct *tsk)
107{}
108static inline void delayacct_tsk_free(struct task_struct *tsk)
109{}
110static inline void delayacct_blkio_start(void)
111{}
112static inline void delayacct_blkio_end(void)
113{}
114static inline int delayacct_add_tsk(struct taskstats *d,
115 struct task_struct *tsk)
116{ return 0; }
117static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
118{ return 0; }
119#endif /* CONFIG_TASK_DELAY_ACCT */
120
121#endif