Merge tag 'linux-can-next-for-4.12-20170427' of git://git.kernel.org/pub/scm/linux...
[linux-2.6/btrfs-unstable.git] / include / linux / delayacct.h
blob4178d24935477da5c02679ddba8dbadc22a48d2a
1 /* delayacct.h - per-task delay accounting
3 * Copyright (C) Shailabh Nagar, IBM Corp. 2006
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.
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.
17 #ifndef _LINUX_DELAYACCT_H
18 #define _LINUX_DELAYACCT_H
20 #include <uapi/linux/taskstats.h>
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
27 #define DELAYACCT_PF_SWAPIN 0x00000001 /* I am doing a swapin */
28 #define DELAYACCT_PF_BLKIO 0x00000002 /* I am waiting on IO */
30 #ifdef CONFIG_TASK_DELAY_ACCT
31 struct task_delay_info {
32 spinlock_t lock;
33 unsigned int flags; /* Private per-task flags */
35 /* For each stat XXX, add following, aligned appropriately
37 * struct timespec XXX_start, XXX_end;
38 * u64 XXX_delay;
39 * u32 XXX_count;
41 * Atomicity of updates to XXX_delay, XXX_count protected by
42 * single lock above (split into XXX_lock if contention is an issue).
46 * XXX_count is incremented on every XXX operation, the delay
47 * associated with the operation is added to XXX_delay.
48 * XXX_delay contains the accumulated delay time in nanoseconds.
50 u64 blkio_start; /* Shared by blkio, swapin */
51 u64 blkio_delay; /* wait for sync block io completion */
52 u64 swapin_delay; /* wait for swapin block io completion */
53 u32 blkio_count; /* total count of the number of sync block */
54 /* io operations performed */
55 u32 swapin_count; /* total count of the number of swapin block */
56 /* io operations performed */
58 u64 freepages_start;
59 u64 freepages_delay; /* wait for memory reclaim */
60 u32 freepages_count; /* total count of memory reclaim */
62 #endif
64 #include <linux/sched.h>
65 #include <linux/slab.h>
67 #ifdef CONFIG_TASK_DELAY_ACCT
68 extern int delayacct_on; /* Delay accounting turned on/off */
69 extern struct kmem_cache *delayacct_cache;
70 extern void delayacct_init(void);
71 extern void __delayacct_tsk_init(struct task_struct *);
72 extern void __delayacct_tsk_exit(struct task_struct *);
73 extern void __delayacct_blkio_start(void);
74 extern void __delayacct_blkio_end(void);
75 extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
76 extern __u64 __delayacct_blkio_ticks(struct task_struct *);
77 extern void __delayacct_freepages_start(void);
78 extern void __delayacct_freepages_end(void);
80 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
82 if (p->delays)
83 return (p->delays->flags & DELAYACCT_PF_BLKIO);
84 else
85 return 0;
88 static inline void delayacct_set_flag(int flag)
90 if (current->delays)
91 current->delays->flags |= flag;
94 static inline void delayacct_clear_flag(int flag)
96 if (current->delays)
97 current->delays->flags &= ~flag;
100 static inline void delayacct_tsk_init(struct task_struct *tsk)
102 /* reinitialize in case parent's non-null pointer was dup'ed*/
103 tsk->delays = NULL;
104 if (delayacct_on)
105 __delayacct_tsk_init(tsk);
108 /* Free tsk->delays. Called from bad fork and __put_task_struct
109 * where there's no risk of tsk->delays being accessed elsewhere
111 static inline void delayacct_tsk_free(struct task_struct *tsk)
113 if (tsk->delays)
114 kmem_cache_free(delayacct_cache, tsk->delays);
115 tsk->delays = NULL;
118 static inline void delayacct_blkio_start(void)
120 delayacct_set_flag(DELAYACCT_PF_BLKIO);
121 if (current->delays)
122 __delayacct_blkio_start();
125 static inline void delayacct_blkio_end(void)
127 if (current->delays)
128 __delayacct_blkio_end();
129 delayacct_clear_flag(DELAYACCT_PF_BLKIO);
132 static inline int delayacct_add_tsk(struct taskstats *d,
133 struct task_struct *tsk)
135 if (!delayacct_on || !tsk->delays)
136 return 0;
137 return __delayacct_add_tsk(d, tsk);
140 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
142 if (tsk->delays)
143 return __delayacct_blkio_ticks(tsk);
144 return 0;
147 static inline void delayacct_freepages_start(void)
149 if (current->delays)
150 __delayacct_freepages_start();
153 static inline void delayacct_freepages_end(void)
155 if (current->delays)
156 __delayacct_freepages_end();
159 #else
160 static inline void delayacct_set_flag(int flag)
162 static inline void delayacct_clear_flag(int flag)
164 static inline void delayacct_init(void)
166 static inline void delayacct_tsk_init(struct task_struct *tsk)
168 static inline void delayacct_tsk_free(struct task_struct *tsk)
170 static inline void delayacct_blkio_start(void)
172 static inline void delayacct_blkio_end(void)
174 static inline int delayacct_add_tsk(struct taskstats *d,
175 struct task_struct *tsk)
176 { return 0; }
177 static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
178 { return 0; }
179 static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
180 { return 0; }
181 static inline void delayacct_freepages_start(void)
183 static inline void delayacct_freepages_end(void)
186 #endif /* CONFIG_TASK_DELAY_ACCT */
188 #endif