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/slab.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 #define DELAYACCT_PF_BLKIO 0x00000002 /* I am waiting on IO */
30
31 #ifdef CONFIG_TASK_DELAY_ACCT
32
33 extern int delayacct_on; /* Delay accounting turned on/off */
34 extern struct kmem_cache *delayacct_cache;
35 extern void delayacct_init(void);
36 extern void __delayacct_tsk_init(struct task_struct *);
37 extern void __delayacct_tsk_exit(struct task_struct *);
38 extern void __delayacct_blkio_start(void);
39 extern void __delayacct_blkio_end(void);
40 extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
41 extern __u64 __delayacct_blkio_ticks(struct task_struct *);
42 extern void __delayacct_freepages_start(void);
43 extern void __delayacct_freepages_end(void);
44
delayacct_is_task_waiting_on_io(struct task_struct * p)45 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
46 {
47 if (p->delays)
48 return (p->delays->flags & DELAYACCT_PF_BLKIO);
49 else
50 return 0;
51 }
52
delayacct_set_flag(int flag)53 static inline void delayacct_set_flag(int flag)
54 {
55 if (current->delays)
56 current->delays->flags |= flag;
57 }
58
delayacct_clear_flag(int flag)59 static inline void delayacct_clear_flag(int flag)
60 {
61 if (current->delays)
62 current->delays->flags &= ~flag;
63 }
64
delayacct_tsk_init(struct task_struct * tsk)65 static inline void delayacct_tsk_init(struct task_struct *tsk)
66 {
67 /* reinitialize in case parent's non-null pointer was dup'ed*/
68 tsk->delays = NULL;
69 if (delayacct_on)
70 __delayacct_tsk_init(tsk);
71 }
72
73 /* Free tsk->delays. Called from bad fork and __put_task_struct
74 * where there's no risk of tsk->delays being accessed elsewhere
75 */
delayacct_tsk_free(struct task_struct * tsk)76 static inline void delayacct_tsk_free(struct task_struct *tsk)
77 {
78 if (tsk->delays)
79 kmem_cache_free(delayacct_cache, tsk->delays);
80 tsk->delays = NULL;
81 }
82
delayacct_blkio_start(void)83 static inline void delayacct_blkio_start(void)
84 {
85 delayacct_set_flag(DELAYACCT_PF_BLKIO);
86 if (current->delays)
87 __delayacct_blkio_start();
88 }
89
delayacct_blkio_end(void)90 static inline void delayacct_blkio_end(void)
91 {
92 if (current->delays)
93 __delayacct_blkio_end();
94 delayacct_clear_flag(DELAYACCT_PF_BLKIO);
95 }
96
delayacct_add_tsk(struct taskstats * d,struct task_struct * tsk)97 static inline int delayacct_add_tsk(struct taskstats *d,
98 struct task_struct *tsk)
99 {
100 if (!delayacct_on || !tsk->delays)
101 return 0;
102 return __delayacct_add_tsk(d, tsk);
103 }
104
delayacct_blkio_ticks(struct task_struct * tsk)105 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
106 {
107 if (tsk->delays)
108 return __delayacct_blkio_ticks(tsk);
109 return 0;
110 }
111
delayacct_freepages_start(void)112 static inline void delayacct_freepages_start(void)
113 {
114 if (current->delays)
115 __delayacct_freepages_start();
116 }
117
delayacct_freepages_end(void)118 static inline void delayacct_freepages_end(void)
119 {
120 if (current->delays)
121 __delayacct_freepages_end();
122 }
123
124 #else
delayacct_set_flag(int flag)125 static inline void delayacct_set_flag(int flag)
126 {}
delayacct_clear_flag(int flag)127 static inline void delayacct_clear_flag(int flag)
128 {}
delayacct_init(void)129 static inline void delayacct_init(void)
130 {}
delayacct_tsk_init(struct task_struct * tsk)131 static inline void delayacct_tsk_init(struct task_struct *tsk)
132 {}
delayacct_tsk_free(struct task_struct * tsk)133 static inline void delayacct_tsk_free(struct task_struct *tsk)
134 {}
delayacct_blkio_start(void)135 static inline void delayacct_blkio_start(void)
136 {}
delayacct_blkio_end(void)137 static inline void delayacct_blkio_end(void)
138 {}
delayacct_add_tsk(struct taskstats * d,struct task_struct * tsk)139 static inline int delayacct_add_tsk(struct taskstats *d,
140 struct task_struct *tsk)
141 { return 0; }
delayacct_blkio_ticks(struct task_struct * tsk)142 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
143 { return 0; }
delayacct_is_task_waiting_on_io(struct task_struct * p)144 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
145 { return 0; }
delayacct_freepages_start(void)146 static inline void delayacct_freepages_start(void)
147 {}
delayacct_freepages_end(void)148 static inline void delayacct_freepages_end(void)
149 {}
150
151 #endif /* CONFIG_TASK_DELAY_ACCT */
152
153 #endif
154