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ca74e92b SN |
1 | /* delayacct.c - 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 would be useful, but | |
11 | * 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 | #include <linux/sched.h> | |
17 | #include <linux/slab.h> | |
6952b61d | 18 | #include <linux/taskstats.h> |
ca74e92b SN |
19 | #include <linux/time.h> |
20 | #include <linux/sysctl.h> | |
21 | #include <linux/delayacct.h> | |
c9aaa895 | 22 | #include <linux/module.h> |
ca74e92b | 23 | |
163ecdff | 24 | int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */ |
c9aaa895 | 25 | EXPORT_SYMBOL_GPL(delayacct_on); |
e18b890b | 26 | struct kmem_cache *delayacct_cache; |
ca74e92b | 27 | |
163ecdff | 28 | static int __init delayacct_setup_disable(char *str) |
ca74e92b | 29 | { |
163ecdff | 30 | delayacct_on = 0; |
ca74e92b SN |
31 | return 1; |
32 | } | |
163ecdff | 33 | __setup("nodelayacct", delayacct_setup_disable); |
ca74e92b SN |
34 | |
35 | void delayacct_init(void) | |
36 | { | |
5d097056 | 37 | delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT); |
ca74e92b SN |
38 | delayacct_tsk_init(&init_task); |
39 | } | |
40 | ||
41 | void __delayacct_tsk_init(struct task_struct *tsk) | |
42 | { | |
e94b1766 | 43 | tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL); |
ca74e92b SN |
44 | if (tsk->delays) |
45 | spin_lock_init(&tsk->delays->lock); | |
46 | } | |
47 | ||
ca74e92b | 48 | /* |
9667a23d TG |
49 | * Finish delay accounting for a statistic using its timestamps (@start), |
50 | * accumalator (@total) and @count | |
ca74e92b | 51 | */ |
9667a23d | 52 | static void delayacct_end(u64 *start, u64 *total, u32 *count) |
ca74e92b | 53 | { |
9667a23d | 54 | s64 ns = ktime_get_ns() - *start; |
64efade1 | 55 | unsigned long flags; |
ca74e92b | 56 | |
9667a23d TG |
57 | if (ns > 0) { |
58 | spin_lock_irqsave(¤t->delays->lock, flags); | |
59 | *total += ns; | |
60 | (*count)++; | |
61 | spin_unlock_irqrestore(¤t->delays->lock, flags); | |
62 | } | |
ca74e92b SN |
63 | } |
64 | ||
0ff92245 SN |
65 | void __delayacct_blkio_start(void) |
66 | { | |
9667a23d | 67 | current->delays->blkio_start = ktime_get_ns(); |
0ff92245 SN |
68 | } |
69 | ||
70 | void __delayacct_blkio_end(void) | |
71 | { | |
72 | if (current->delays->flags & DELAYACCT_PF_SWAPIN) | |
73 | /* Swapin block I/O */ | |
74 | delayacct_end(¤t->delays->blkio_start, | |
0ff92245 SN |
75 | ¤t->delays->swapin_delay, |
76 | ¤t->delays->swapin_count); | |
77 | else /* Other block I/O */ | |
78 | delayacct_end(¤t->delays->blkio_start, | |
0ff92245 SN |
79 | ¤t->delays->blkio_delay, |
80 | ¤t->delays->blkio_count); | |
81 | } | |
6f44993f SN |
82 | |
83 | int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) | |
84 | { | |
6fac4829 | 85 | cputime_t utime, stime, stimescaled, utimescaled; |
68f6783d TG |
86 | unsigned long long t2, t3; |
87 | unsigned long flags, t1; | |
88 | s64 tmp; | |
6f44993f | 89 | |
6fac4829 | 90 | task_cputime(tsk, &utime, &stime); |
68f6783d TG |
91 | tmp = (s64)d->cpu_run_real_total; |
92 | tmp += cputime_to_nsecs(utime + stime); | |
6f44993f SN |
93 | d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp; |
94 | ||
6fac4829 | 95 | task_cputime_scaled(tsk, &utimescaled, &stimescaled); |
68f6783d TG |
96 | tmp = (s64)d->cpu_scaled_run_real_total; |
97 | tmp += cputime_to_nsecs(utimescaled + stimescaled); | |
c66f08be MN |
98 | d->cpu_scaled_run_real_total = |
99 | (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp; | |
100 | ||
6f44993f SN |
101 | /* |
102 | * No locking available for sched_info (and too expensive to add one) | |
103 | * Mitigate by taking snapshot of values | |
104 | */ | |
2d72376b | 105 | t1 = tsk->sched_info.pcount; |
6f44993f | 106 | t2 = tsk->sched_info.run_delay; |
9c2c4802 | 107 | t3 = tsk->se.sum_exec_runtime; |
6f44993f SN |
108 | |
109 | d->cpu_count += t1; | |
110 | ||
172ba844 | 111 | tmp = (s64)d->cpu_delay_total + t2; |
6f44993f SN |
112 | d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp; |
113 | ||
172ba844 | 114 | tmp = (s64)d->cpu_run_virtual_total + t3; |
6f44993f SN |
115 | d->cpu_run_virtual_total = |
116 | (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp; | |
117 | ||
118 | /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ | |
119 | ||
64efade1 | 120 | spin_lock_irqsave(&tsk->delays->lock, flags); |
6f44993f SN |
121 | tmp = d->blkio_delay_total + tsk->delays->blkio_delay; |
122 | d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp; | |
123 | tmp = d->swapin_delay_total + tsk->delays->swapin_delay; | |
124 | d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp; | |
016ae219 KK |
125 | tmp = d->freepages_delay_total + tsk->delays->freepages_delay; |
126 | d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp; | |
6f44993f SN |
127 | d->blkio_count += tsk->delays->blkio_count; |
128 | d->swapin_count += tsk->delays->swapin_count; | |
016ae219 | 129 | d->freepages_count += tsk->delays->freepages_count; |
64efade1 | 130 | spin_unlock_irqrestore(&tsk->delays->lock, flags); |
6f44993f | 131 | |
6f44993f SN |
132 | return 0; |
133 | } | |
25890454 SN |
134 | |
135 | __u64 __delayacct_blkio_ticks(struct task_struct *tsk) | |
136 | { | |
137 | __u64 ret; | |
64efade1 | 138 | unsigned long flags; |
25890454 | 139 | |
64efade1 | 140 | spin_lock_irqsave(&tsk->delays->lock, flags); |
25890454 SN |
141 | ret = nsec_to_clock_t(tsk->delays->blkio_delay + |
142 | tsk->delays->swapin_delay); | |
64efade1 | 143 | spin_unlock_irqrestore(&tsk->delays->lock, flags); |
25890454 SN |
144 | return ret; |
145 | } | |
146 | ||
873b4771 KK |
147 | void __delayacct_freepages_start(void) |
148 | { | |
9667a23d | 149 | current->delays->freepages_start = ktime_get_ns(); |
873b4771 KK |
150 | } |
151 | ||
152 | void __delayacct_freepages_end(void) | |
153 | { | |
154 | delayacct_end(¤t->delays->freepages_start, | |
873b4771 KK |
155 | ¤t->delays->freepages_delay, |
156 | ¤t->delays->freepages_count); | |
157 | } | |
158 |