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Thomas Gleixner71700662019-05-19 15:51:55 +02001// SPDX-License-Identifier: GPL-2.0-or-later
Shailabh Nagarca74e922006-07-14 00:24:36 -07002/* delayacct.c - per-task delay accounting
3 *
4 * Copyright (C) Shailabh Nagar, IBM Corp. 2006
Shailabh Nagarca74e922006-07-14 00:24:36 -07005 */
6
7#include <linux/sched.h>
Ingo Molnar9164bb42017-02-04 01:20:53 +01008#include <linux/sched/task.h>
Ingo Molnar32ef5512017-02-05 11:48:36 +01009#include <linux/sched/cputime.h>
Peter Zijlstra4b7a08a2021-05-04 22:43:48 +020010#include <linux/sched/clock.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070011#include <linux/slab.h>
Alexey Dobriyan6952b612009-09-18 23:55:55 +040012#include <linux/taskstats.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070013#include <linux/sysctl.h>
14#include <linux/delayacct.h>
Glauber Costac9aaa892011-07-11 15:28:14 -040015#include <linux/module.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070016
Peter Zijlstrae4042ad2021-05-04 22:43:32 +020017DEFINE_STATIC_KEY_FALSE(delayacct_key);
18int delayacct_on __read_mostly; /* Delay accounting turned on/off */
Christoph Lametere18b8902006-12-06 20:33:20 -080019struct kmem_cache *delayacct_cache;
Shailabh Nagarca74e922006-07-14 00:24:36 -070020
Peter Zijlstra0cd7c742021-05-10 14:01:00 +020021static void set_delayacct(bool enabled)
22{
23 if (enabled) {
24 static_branch_enable(&delayacct_key);
25 delayacct_on = 1;
26 } else {
27 delayacct_on = 0;
28 static_branch_disable(&delayacct_key);
29 }
30}
31
Peter Zijlstrae4042ad2021-05-04 22:43:32 +020032static int __init delayacct_setup_enable(char *str)
Shailabh Nagarca74e922006-07-14 00:24:36 -070033{
Peter Zijlstrae4042ad2021-05-04 22:43:32 +020034 delayacct_on = 1;
Shailabh Nagarca74e922006-07-14 00:24:36 -070035 return 1;
36}
Peter Zijlstrae4042ad2021-05-04 22:43:32 +020037__setup("delayacct", delayacct_setup_enable);
Shailabh Nagarca74e922006-07-14 00:24:36 -070038
39void delayacct_init(void)
40{
Vladimir Davydov5d097052016-01-14 15:18:21 -080041 delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT);
Shailabh Nagarca74e922006-07-14 00:24:36 -070042 delayacct_tsk_init(&init_task);
Peter Zijlstra0cd7c742021-05-10 14:01:00 +020043 set_delayacct(delayacct_on);
Shailabh Nagarca74e922006-07-14 00:24:36 -070044}
45
Peter Zijlstra0cd7c742021-05-10 14:01:00 +020046#ifdef CONFIG_PROC_SYSCTL
tangmeng11866182022-02-18 18:59:36 +080047static int sysctl_delayacct(struct ctl_table *table, int write, void *buffer,
Peter Zijlstra0cd7c742021-05-10 14:01:00 +020048 size_t *lenp, loff_t *ppos)
49{
50 int state = delayacct_on;
51 struct ctl_table t;
52 int err;
53
54 if (write && !capable(CAP_SYS_ADMIN))
55 return -EPERM;
56
57 t = *table;
58 t.data = &state;
59 err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
60 if (err < 0)
61 return err;
62 if (write)
63 set_delayacct(state);
64 return err;
65}
tangmeng11866182022-02-18 18:59:36 +080066
67static struct ctl_table kern_delayacct_table[] = {
68 {
69 .procname = "task_delayacct",
70 .data = NULL,
71 .maxlen = sizeof(unsigned int),
72 .mode = 0644,
73 .proc_handler = sysctl_delayacct,
74 .extra1 = SYSCTL_ZERO,
75 .extra2 = SYSCTL_ONE,
76 },
77 { }
78};
79
80static __init int kernel_delayacct_sysctls_init(void)
81{
82 register_sysctl_init("kernel", kern_delayacct_table);
83 return 0;
84}
85late_initcall(kernel_delayacct_sysctls_init);
Peter Zijlstra0cd7c742021-05-10 14:01:00 +020086#endif
87
Shailabh Nagarca74e922006-07-14 00:24:36 -070088void __delayacct_tsk_init(struct task_struct *tsk)
89{
Christoph Lametere94b1762006-12-06 20:33:17 -080090 tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL);
Shailabh Nagarca74e922006-07-14 00:24:36 -070091 if (tsk->delays)
Sebastian Andrzej Siewior02acc802018-04-23 18:10:23 +020092 raw_spin_lock_init(&tsk->delays->lock);
Shailabh Nagarca74e922006-07-14 00:24:36 -070093}
94
Shailabh Nagarca74e922006-07-14 00:24:36 -070095/*
Thomas Gleixner9667a232014-07-16 21:04:35 +000096 * Finish delay accounting for a statistic using its timestamps (@start),
97 * accumalator (@total) and @count
Shailabh Nagarca74e922006-07-14 00:24:36 -070098 */
Peter Zijlstra4b7a08a2021-05-04 22:43:48 +020099static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total, u32 *count)
Shailabh Nagarca74e922006-07-14 00:24:36 -0700100{
Peter Zijlstra4b7a08a2021-05-04 22:43:48 +0200101 s64 ns = local_clock() - *start;
Peter Zijlstra64efade2006-11-05 23:52:10 -0800102 unsigned long flags;
Shailabh Nagarca74e922006-07-14 00:24:36 -0700103
Thomas Gleixner9667a232014-07-16 21:04:35 +0000104 if (ns > 0) {
Sebastian Andrzej Siewior02acc802018-04-23 18:10:23 +0200105 raw_spin_lock_irqsave(lock, flags);
Thomas Gleixner9667a232014-07-16 21:04:35 +0000106 *total += ns;
107 (*count)++;
Sebastian Andrzej Siewior02acc802018-04-23 18:10:23 +0200108 raw_spin_unlock_irqrestore(lock, flags);
Thomas Gleixner9667a232014-07-16 21:04:35 +0000109 }
Shailabh Nagarca74e922006-07-14 00:24:36 -0700110}
111
Shailabh Nagar0ff92242006-07-14 00:24:37 -0700112void __delayacct_blkio_start(void)
113{
Peter Zijlstra4b7a08a2021-05-04 22:43:48 +0200114 current->delays->blkio_start = local_clock();
Shailabh Nagar0ff92242006-07-14 00:24:37 -0700115}
116
Josh Snyderc96f5472017-12-18 16:15:10 +0000117/*
118 * We cannot rely on the `current` macro, as we haven't yet switched back to
119 * the process being woken.
120 */
121void __delayacct_blkio_end(struct task_struct *p)
Shailabh Nagar0ff92242006-07-14 00:24:37 -0700122{
Yang Yanga3d5dc92022-01-19 18:10:02 -0800123 delayacct_end(&p->delays->lock,
124 &p->delays->blkio_start,
125 &p->delays->blkio_delay,
126 &p->delays->blkio_count);
Shailabh Nagar0ff92242006-07-14 00:24:37 -0700127}
Shailabh Nagar6f449932006-07-14 00:24:41 -0700128
Peter Zijlstrae4042ad2021-05-04 22:43:32 +0200129int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
Shailabh Nagar6f449932006-07-14 00:24:41 -0700130{
Frederic Weisbeckerdbf3da12017-01-31 04:09:29 +0100131 u64 utime, stime, stimescaled, utimescaled;
Thomas Gleixner68f6783d2014-07-16 21:04:37 +0000132 unsigned long long t2, t3;
133 unsigned long flags, t1;
134 s64 tmp;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700135
Frederic Weisbeckerdbf3da12017-01-31 04:09:29 +0100136 task_cputime(tsk, &utime, &stime);
Thomas Gleixner68f6783d2014-07-16 21:04:37 +0000137 tmp = (s64)d->cpu_run_real_total;
Frederic Weisbeckerdbf3da12017-01-31 04:09:29 +0100138 tmp += utime + stime;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700139 d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
140
Frederic Weisbeckerdbf3da12017-01-31 04:09:29 +0100141 task_cputime_scaled(tsk, &utimescaled, &stimescaled);
Thomas Gleixner68f6783d2014-07-16 21:04:37 +0000142 tmp = (s64)d->cpu_scaled_run_real_total;
Frederic Weisbeckerdbf3da12017-01-31 04:09:29 +0100143 tmp += utimescaled + stimescaled;
Michael Neulingc66f08b2007-10-18 03:06:34 -0700144 d->cpu_scaled_run_real_total =
145 (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;
146
Shailabh Nagar6f449932006-07-14 00:24:41 -0700147 /*
148 * No locking available for sched_info (and too expensive to add one)
149 * Mitigate by taking snapshot of values
150 */
Ingo Molnar2d723762007-10-15 17:00:12 +0200151 t1 = tsk->sched_info.pcount;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700152 t2 = tsk->sched_info.run_delay;
Ken Chen9c2c4802008-12-16 23:41:22 -0800153 t3 = tsk->se.sum_exec_runtime;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700154
155 d->cpu_count += t1;
156
Balbir Singh172ba842007-07-09 18:52:00 +0200157 tmp = (s64)d->cpu_delay_total + t2;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700158 d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp;
159
Balbir Singh172ba842007-07-09 18:52:00 +0200160 tmp = (s64)d->cpu_run_virtual_total + t3;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700161 d->cpu_run_virtual_total =
162 (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp;
163
Peter Zijlstrae4042ad2021-05-04 22:43:32 +0200164 if (!tsk->delays)
165 return 0;
166
Shailabh Nagar6f449932006-07-14 00:24:41 -0700167 /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */
168
Sebastian Andrzej Siewior02acc802018-04-23 18:10:23 +0200169 raw_spin_lock_irqsave(&tsk->delays->lock, flags);
Shailabh Nagar6f449932006-07-14 00:24:41 -0700170 tmp = d->blkio_delay_total + tsk->delays->blkio_delay;
171 d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp;
172 tmp = d->swapin_delay_total + tsk->delays->swapin_delay;
173 d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp;
Keika Kobayashi016ae212008-07-25 01:48:53 -0700174 tmp = d->freepages_delay_total + tsk->delays->freepages_delay;
175 d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp;
Johannes Weinerb1d29ba2018-10-26 15:06:08 -0700176 tmp = d->thrashing_delay_total + tsk->delays->thrashing_delay;
177 d->thrashing_delay_total = (tmp < d->thrashing_delay_total) ? 0 : tmp;
wangyong5bf18282022-01-19 18:10:15 -0800178 tmp = d->compact_delay_total + tsk->delays->compact_delay;
179 d->compact_delay_total = (tmp < d->compact_delay_total) ? 0 : tmp;
Yang Yang662ce1d2022-06-01 15:55:25 -0700180 tmp = d->wpcopy_delay_total + tsk->delays->wpcopy_delay;
181 d->wpcopy_delay_total = (tmp < d->wpcopy_delay_total) ? 0 : tmp;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700182 d->blkio_count += tsk->delays->blkio_count;
183 d->swapin_count += tsk->delays->swapin_count;
Keika Kobayashi016ae212008-07-25 01:48:53 -0700184 d->freepages_count += tsk->delays->freepages_count;
Johannes Weinerb1d29ba2018-10-26 15:06:08 -0700185 d->thrashing_count += tsk->delays->thrashing_count;
wangyong5bf18282022-01-19 18:10:15 -0800186 d->compact_count += tsk->delays->compact_count;
Yang Yang662ce1d2022-06-01 15:55:25 -0700187 d->wpcopy_count += tsk->delays->wpcopy_count;
Sebastian Andrzej Siewior02acc802018-04-23 18:10:23 +0200188 raw_spin_unlock_irqrestore(&tsk->delays->lock, flags);
Shailabh Nagar6f449932006-07-14 00:24:41 -0700189
Shailabh Nagar6f449932006-07-14 00:24:41 -0700190 return 0;
191}
Shailabh Nagar25890452006-07-14 00:24:43 -0700192
193__u64 __delayacct_blkio_ticks(struct task_struct *tsk)
194{
195 __u64 ret;
Peter Zijlstra64efade2006-11-05 23:52:10 -0800196 unsigned long flags;
Shailabh Nagar25890452006-07-14 00:24:43 -0700197
Sebastian Andrzej Siewior02acc802018-04-23 18:10:23 +0200198 raw_spin_lock_irqsave(&tsk->delays->lock, flags);
Yang Yanga3d5dc92022-01-19 18:10:02 -0800199 ret = nsec_to_clock_t(tsk->delays->blkio_delay);
Sebastian Andrzej Siewior02acc802018-04-23 18:10:23 +0200200 raw_spin_unlock_irqrestore(&tsk->delays->lock, flags);
Shailabh Nagar25890452006-07-14 00:24:43 -0700201 return ret;
202}
203
Keika Kobayashi873b4772008-07-25 01:48:52 -0700204void __delayacct_freepages_start(void)
205{
Peter Zijlstra4b7a08a2021-05-04 22:43:48 +0200206 current->delays->freepages_start = local_clock();
Keika Kobayashi873b4772008-07-25 01:48:52 -0700207}
208
209void __delayacct_freepages_end(void)
210{
Peter Zijlstra4b7a08a2021-05-04 22:43:48 +0200211 delayacct_end(&current->delays->lock,
212 &current->delays->freepages_start,
213 &current->delays->freepages_delay,
214 &current->delays->freepages_count);
Keika Kobayashi873b4772008-07-25 01:48:52 -0700215}
216
Yang Yangaa1cf992022-08-15 07:11:35 +0000217void __delayacct_thrashing_start(bool *in_thrashing)
Johannes Weinerb1d29ba2018-10-26 15:06:08 -0700218{
Yang Yangaa1cf992022-08-15 07:11:35 +0000219 *in_thrashing = !!current->in_thrashing;
220 if (*in_thrashing)
221 return;
222
223 current->in_thrashing = 1;
Peter Zijlstra4b7a08a2021-05-04 22:43:48 +0200224 current->delays->thrashing_start = local_clock();
Johannes Weinerb1d29ba2018-10-26 15:06:08 -0700225}
226
Yang Yangaa1cf992022-08-15 07:11:35 +0000227void __delayacct_thrashing_end(bool *in_thrashing)
Johannes Weinerb1d29ba2018-10-26 15:06:08 -0700228{
Yang Yangaa1cf992022-08-15 07:11:35 +0000229 if (*in_thrashing)
230 return;
231
232 current->in_thrashing = 0;
Johannes Weinerb1d29ba2018-10-26 15:06:08 -0700233 delayacct_end(&current->delays->lock,
234 &current->delays->thrashing_start,
235 &current->delays->thrashing_delay,
236 &current->delays->thrashing_count);
237}
Yang Yanga3d5dc92022-01-19 18:10:02 -0800238
239void __delayacct_swapin_start(void)
240{
241 current->delays->swapin_start = local_clock();
242}
243
244void __delayacct_swapin_end(void)
245{
246 delayacct_end(&current->delays->lock,
247 &current->delays->swapin_start,
248 &current->delays->swapin_delay,
249 &current->delays->swapin_count);
250}
wangyong5bf18282022-01-19 18:10:15 -0800251
252void __delayacct_compact_start(void)
253{
254 current->delays->compact_start = local_clock();
255}
256
257void __delayacct_compact_end(void)
258{
259 delayacct_end(&current->delays->lock,
260 &current->delays->compact_start,
261 &current->delays->compact_delay,
262 &current->delays->compact_count);
263}
Yang Yang662ce1d2022-06-01 15:55:25 -0700264
265void __delayacct_wpcopy_start(void)
266{
267 current->delays->wpcopy_start = local_clock();
268}
269
270void __delayacct_wpcopy_end(void)
271{
272 delayacct_end(&current->delays->lock,
273 &current->delays->wpcopy_start,
274 &current->delays->wpcopy_delay,
275 &current->delays->wpcopy_count);
276}