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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> | |
9164bb4a | 17 | #include <linux/sched/task.h> |
32ef5517 | 18 | #include <linux/sched/cputime.h> |
ca74e92b | 19 | #include <linux/slab.h> |
6952b61d | 20 | #include <linux/taskstats.h> |
ca74e92b SN |
21 | #include <linux/time.h> |
22 | #include <linux/sysctl.h> | |
23 | #include <linux/delayacct.h> | |
c9aaa895 | 24 | #include <linux/module.h> |
ca74e92b | 25 | |
163ecdff | 26 | int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */ |
c9aaa895 | 27 | EXPORT_SYMBOL_GPL(delayacct_on); |
e18b890b | 28 | struct kmem_cache *delayacct_cache; |
ca74e92b | 29 | |
163ecdff | 30 | static int __init delayacct_setup_disable(char *str) |
ca74e92b | 31 | { |
163ecdff | 32 | delayacct_on = 0; |
ca74e92b SN |
33 | return 1; |
34 | } | |
163ecdff | 35 | __setup("nodelayacct", delayacct_setup_disable); |
ca74e92b SN |
36 | |
37 | void delayacct_init(void) | |
38 | { | |
5d097056 | 39 | delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT); |
ca74e92b SN |
40 | delayacct_tsk_init(&init_task); |
41 | } | |
42 | ||
43 | void __delayacct_tsk_init(struct task_struct *tsk) | |
44 | { | |
e94b1766 | 45 | tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL); |
ca74e92b SN |
46 | if (tsk->delays) |
47 | spin_lock_init(&tsk->delays->lock); | |
48 | } | |
49 | ||
ca74e92b | 50 | /* |
9667a23d TG |
51 | * Finish delay accounting for a statistic using its timestamps (@start), |
52 | * accumalator (@total) and @count | |
ca74e92b | 53 | */ |
c96f5471 | 54 | static void delayacct_end(spinlock_t *lock, u64 *start, u64 *total, u32 *count) |
ca74e92b | 55 | { |
9667a23d | 56 | s64 ns = ktime_get_ns() - *start; |
64efade1 | 57 | unsigned long flags; |
ca74e92b | 58 | |
9667a23d | 59 | if (ns > 0) { |
c96f5471 | 60 | spin_lock_irqsave(lock, flags); |
9667a23d TG |
61 | *total += ns; |
62 | (*count)++; | |
c96f5471 | 63 | spin_unlock_irqrestore(lock, flags); |
9667a23d | 64 | } |
ca74e92b SN |
65 | } |
66 | ||
0ff92245 SN |
67 | void __delayacct_blkio_start(void) |
68 | { | |
9667a23d | 69 | current->delays->blkio_start = ktime_get_ns(); |
0ff92245 SN |
70 | } |
71 | ||
c96f5471 JS |
72 | /* |
73 | * We cannot rely on the `current` macro, as we haven't yet switched back to | |
74 | * the process being woken. | |
75 | */ | |
76 | void __delayacct_blkio_end(struct task_struct *p) | |
0ff92245 | 77 | { |
c96f5471 JS |
78 | struct task_delay_info *delays = p->delays; |
79 | u64 *total; | |
80 | u32 *count; | |
81 | ||
82 | if (p->delays->flags & DELAYACCT_PF_SWAPIN) { | |
83 | total = &delays->swapin_delay; | |
84 | count = &delays->swapin_count; | |
85 | } else { | |
86 | total = &delays->blkio_delay; | |
87 | count = &delays->blkio_count; | |
88 | } | |
89 | ||
90 | delayacct_end(&delays->lock, &delays->blkio_start, total, count); | |
0ff92245 | 91 | } |
6f44993f SN |
92 | |
93 | int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) | |
94 | { | |
dbf3da1c | 95 | u64 utime, stime, stimescaled, utimescaled; |
68f6783d TG |
96 | unsigned long long t2, t3; |
97 | unsigned long flags, t1; | |
98 | s64 tmp; | |
6f44993f | 99 | |
dbf3da1c | 100 | task_cputime(tsk, &utime, &stime); |
68f6783d | 101 | tmp = (s64)d->cpu_run_real_total; |
dbf3da1c | 102 | tmp += utime + stime; |
6f44993f SN |
103 | d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp; |
104 | ||
dbf3da1c | 105 | task_cputime_scaled(tsk, &utimescaled, &stimescaled); |
68f6783d | 106 | tmp = (s64)d->cpu_scaled_run_real_total; |
dbf3da1c | 107 | tmp += utimescaled + stimescaled; |
c66f08be MN |
108 | d->cpu_scaled_run_real_total = |
109 | (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp; | |
110 | ||
6f44993f SN |
111 | /* |
112 | * No locking available for sched_info (and too expensive to add one) | |
113 | * Mitigate by taking snapshot of values | |
114 | */ | |
2d72376b | 115 | t1 = tsk->sched_info.pcount; |
6f44993f | 116 | t2 = tsk->sched_info.run_delay; |
9c2c4802 | 117 | t3 = tsk->se.sum_exec_runtime; |
6f44993f SN |
118 | |
119 | d->cpu_count += t1; | |
120 | ||
172ba844 | 121 | tmp = (s64)d->cpu_delay_total + t2; |
6f44993f SN |
122 | d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp; |
123 | ||
172ba844 | 124 | tmp = (s64)d->cpu_run_virtual_total + t3; |
6f44993f SN |
125 | d->cpu_run_virtual_total = |
126 | (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp; | |
127 | ||
128 | /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */ | |
129 | ||
64efade1 | 130 | spin_lock_irqsave(&tsk->delays->lock, flags); |
6f44993f SN |
131 | tmp = d->blkio_delay_total + tsk->delays->blkio_delay; |
132 | d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp; | |
133 | tmp = d->swapin_delay_total + tsk->delays->swapin_delay; | |
134 | d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp; | |
016ae219 KK |
135 | tmp = d->freepages_delay_total + tsk->delays->freepages_delay; |
136 | d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp; | |
6f44993f SN |
137 | d->blkio_count += tsk->delays->blkio_count; |
138 | d->swapin_count += tsk->delays->swapin_count; | |
016ae219 | 139 | d->freepages_count += tsk->delays->freepages_count; |
64efade1 | 140 | spin_unlock_irqrestore(&tsk->delays->lock, flags); |
6f44993f | 141 | |
6f44993f SN |
142 | return 0; |
143 | } | |
25890454 SN |
144 | |
145 | __u64 __delayacct_blkio_ticks(struct task_struct *tsk) | |
146 | { | |
147 | __u64 ret; | |
64efade1 | 148 | unsigned long flags; |
25890454 | 149 | |
64efade1 | 150 | spin_lock_irqsave(&tsk->delays->lock, flags); |
25890454 SN |
151 | ret = nsec_to_clock_t(tsk->delays->blkio_delay + |
152 | tsk->delays->swapin_delay); | |
64efade1 | 153 | spin_unlock_irqrestore(&tsk->delays->lock, flags); |
25890454 SN |
154 | return ret; |
155 | } | |
156 | ||
873b4771 KK |
157 | void __delayacct_freepages_start(void) |
158 | { | |
9667a23d | 159 | current->delays->freepages_start = ktime_get_ns(); |
873b4771 KK |
160 | } |
161 | ||
162 | void __delayacct_freepages_end(void) | |
163 | { | |
c96f5471 JS |
164 | delayacct_end( |
165 | ¤t->delays->lock, | |
166 | ¤t->delays->freepages_start, | |
167 | ¤t->delays->freepages_delay, | |
168 | ¤t->delays->freepages_count); | |
873b4771 KK |
169 | } |
170 |