headers: taskstats_kern.h trim
[linux-3.10.git] / 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 #define DELAYACCT_PF_BLKIO      0x00000002      /* I am waiting on IO */
29
30 #ifdef CONFIG_TASK_DELAY_ACCT
31
32 extern int delayacct_on;        /* Delay accounting turned on/off */
33 extern struct kmem_cache *delayacct_cache;
34 extern void delayacct_init(void);
35 extern void __delayacct_tsk_init(struct task_struct *);
36 extern void __delayacct_tsk_exit(struct task_struct *);
37 extern void __delayacct_blkio_start(void);
38 extern void __delayacct_blkio_end(void);
39 extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
40 extern __u64 __delayacct_blkio_ticks(struct task_struct *);
41 extern void __delayacct_freepages_start(void);
42 extern void __delayacct_freepages_end(void);
43
44 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
45 {
46         if (p->delays)
47                 return (p->delays->flags & DELAYACCT_PF_BLKIO);
48         else
49                 return 0;
50 }
51
52 static inline void delayacct_set_flag(int flag)
53 {
54         if (current->delays)
55                 current->delays->flags |= flag;
56 }
57
58 static inline void delayacct_clear_flag(int flag)
59 {
60         if (current->delays)
61                 current->delays->flags &= ~flag;
62 }
63
64 static inline void delayacct_tsk_init(struct task_struct *tsk)
65 {
66         /* reinitialize in case parent's non-null pointer was dup'ed*/
67         tsk->delays = NULL;
68         if (delayacct_on)
69                 __delayacct_tsk_init(tsk);
70 }
71
72 /* Free tsk->delays. Called from bad fork and __put_task_struct
73  * where there's no risk of tsk->delays being accessed elsewhere
74  */
75 static inline void delayacct_tsk_free(struct task_struct *tsk)
76 {
77         if (tsk->delays)
78                 kmem_cache_free(delayacct_cache, tsk->delays);
79         tsk->delays = NULL;
80 }
81
82 static inline void delayacct_blkio_start(void)
83 {
84         delayacct_set_flag(DELAYACCT_PF_BLKIO);
85         if (current->delays)
86                 __delayacct_blkio_start();
87 }
88
89 static inline void delayacct_blkio_end(void)
90 {
91         if (current->delays)
92                 __delayacct_blkio_end();
93         delayacct_clear_flag(DELAYACCT_PF_BLKIO);
94 }
95
96 static inline int delayacct_add_tsk(struct taskstats *d,
97                                         struct task_struct *tsk)
98 {
99         if (!delayacct_on || !tsk->delays)
100                 return 0;
101         return __delayacct_add_tsk(d, tsk);
102 }
103
104 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
105 {
106         if (tsk->delays)
107                 return __delayacct_blkio_ticks(tsk);
108         return 0;
109 }
110
111 static inline void delayacct_freepages_start(void)
112 {
113         if (current->delays)
114                 __delayacct_freepages_start();
115 }
116
117 static inline void delayacct_freepages_end(void)
118 {
119         if (current->delays)
120                 __delayacct_freepages_end();
121 }
122
123 #else
124 static inline void delayacct_set_flag(int flag)
125 {}
126 static inline void delayacct_clear_flag(int flag)
127 {}
128 static inline void delayacct_init(void)
129 {}
130 static inline void delayacct_tsk_init(struct task_struct *tsk)
131 {}
132 static inline void delayacct_tsk_free(struct task_struct *tsk)
133 {}
134 static inline void delayacct_blkio_start(void)
135 {}
136 static inline void delayacct_blkio_end(void)
137 {}
138 static inline int delayacct_add_tsk(struct taskstats *d,
139                                         struct task_struct *tsk)
140 { return 0; }
141 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
142 { return 0; }
143 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
144 { return 0; }
145 static inline void delayacct_freepages_start(void)
146 {}
147 static inline void delayacct_freepages_end(void)
148 {}
149
150 #endif /* CONFIG_TASK_DELAY_ACCT */
151
152 #endif