aboutsummaryrefslogtreecommitdiff
path: root/include/linux/delayacct.h
blob: e6c0448ebcc7f3f9c10b0b4ccdfb593d256a3b88 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/* delayacct.h - per-task delay accounting
 *
 * Copyright (C) Shailabh Nagar, IBM Corp. 2006
 *
 * This program is free software;  you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY;  without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 * the GNU General Public License for more details.
 *
 */

#ifndef _LINUX_DELAYACCT_H
#define _LINUX_DELAYACCT_H

#include <uapi/linux/taskstats.h>

/*
 * Per-task flags relevant to delay accounting
 * maintained privately to avoid exhausting similar flags in sched.h:PF_*
 * Used to set current->delays->flags
 */
#define DELAYACCT_PF_SWAPIN	0x00000001	/* I am doing a swapin */
#define DELAYACCT_PF_BLKIO	0x00000002	/* I am waiting on IO */

#ifdef CONFIG_TASK_DELAY_ACCT
struct task_delay_info {
	raw_spinlock_t	lock;
	unsigned int	flags;	/* Private per-task flags */

	/* For each stat XXX, add following, aligned appropriately
	 *
	 * struct timespec XXX_start, XXX_end;
	 * u64 XXX_delay;
	 * u32 XXX_count;
	 *
	 * Atomicity of updates to XXX_delay, XXX_count protected by
	 * single lock above (split into XXX_lock if contention is an issue).
	 */

	/*
	 * XXX_count is incremented on every XXX operation, the delay
	 * associated with the operation is added to XXX_delay.
	 * XXX_delay contains the accumulated delay time in nanoseconds.
	 */
	u64 blkio_start;	/* Shared by blkio, swapin */
	u64 blkio_delay;	/* wait for sync block io completion */
	u64 swapin_delay;	/* wait for swapin block io completion */
	u32 blkio_count;	/* total count of the number of sync block */
				/* io operations performed */
	u32 swapin_count;	/* total count of the number of swapin block */
				/* io operations performed */

	u64 freepages_start;
	u64 freepages_delay;	/* wait for memory reclaim */
	u32 freepages_count;	/* total count of memory reclaim */
};
#endif

#include <linux/sched.h>
#include <linux/slab.h>

#ifdef CONFIG_TASK_DELAY_ACCT
extern int delayacct_on;	/* Delay accounting turned on/off */
extern struct kmem_cache *delayacct_cache;
extern void delayacct_init(void);
extern void __delayacct_tsk_init(struct task_struct *);
extern void __delayacct_tsk_exit(struct task_struct *);
extern void __delayacct_blkio_start(void);
extern void __delayacct_blkio_end(struct task_struct *);
extern int __delayacct_add_tsk(struct taskstats *, struct task_struct *);
extern __u64 __delayacct_blkio_ticks(struct task_struct *);
extern void __delayacct_freepages_start(void);
extern void __delayacct_freepages_end(void);

static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
{
	if (p->delays)
		return (p->delays->flags & DELAYACCT_PF_BLKIO);
	else
		return 0;
}

static inline void delayacct_set_flag(int flag)
{
	if (current->delays)
		current->delays->flags |= flag;
}

static inline void delayacct_clear_flag(int flag)
{
	if (current->delays)
		current->delays->flags &= ~flag;
}

static inline void delayacct_tsk_init(struct task_struct *tsk)
{
	/* reinitialize in case parent's non-null pointer was dup'ed*/
	tsk->delays = NULL;
	if (delayacct_on)
		__delayacct_tsk_init(tsk);
}

/* Free tsk->delays. Called from bad fork and __put_task_struct
 * where there's no risk of tsk->delays being accessed elsewhere
 */
static inline void delayacct_tsk_free(struct task_struct *tsk)
{
	if (tsk->delays)
		kmem_cache_free(delayacct_cache, tsk->delays);
	tsk->delays = NULL;
}

static inline void delayacct_blkio_start(void)
{
	delayacct_set_flag(DELAYACCT_PF_BLKIO);
	if (current->delays)
		__delayacct_blkio_start();
}

static inline void delayacct_blkio_end(struct task_struct *p)
{
	if (current->delays)
		__delayacct_blkio_end(p);
	delayacct_clear_flag(DELAYACCT_PF_BLKIO);
}

static inline int delayacct_add_tsk(struct taskstats *d,
					struct task_struct *tsk)
{
	if (!delayacct_on || !tsk->delays)
		return 0;
	return __delayacct_add_tsk(d, tsk);
}

static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
{
	if (tsk->delays)
		return __delayacct_blkio_ticks(tsk);
	return 0;
}

static inline void delayacct_freepages_start(void)
{
	if (current->delays)
		__delayacct_freepages_start();
}

static inline void delayacct_freepages_end(void)
{
	if (current->delays)
		__delayacct_freepages_end();
}

#else
static inline void delayacct_set_flag(int flag)
{}
static inline void delayacct_clear_flag(int flag)
{}
static inline void delayacct_init(void)
{}
static inline void delayacct_tsk_init(struct task_struct *tsk)
{}
static inline void delayacct_tsk_free(struct task_struct *tsk)
{}
static inline void delayacct_blkio_start(void)
{}
static inline void delayacct_blkio_end(struct task_struct *p)
{}
static inline int delayacct_add_tsk(struct taskstats *d,
					struct task_struct *tsk)
{ return 0; }
static inline __u64 delayacct_blkio_ticks(struct task_struct *tsk)
{ return 0; }
static inline int delayacct_is_task_waiting_on_io(struct task_struct *p)
{ return 0; }
static inline void delayacct_freepages_start(void)
{}
static inline void delayacct_freepages_end(void)
{}

#endif /* CONFIG_TASK_DELAY_ACCT */

#endif