Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[platform/kernel/linux-rpi.git] / kernel / delayacct.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* delayacct.c - per-task delay accounting
3  *
4  * Copyright (C) Shailabh Nagar, IBM Corp. 2006
5  */
6
7 #include <linux/sched.h>
8 #include <linux/sched/task.h>
9 #include <linux/sched/cputime.h>
10 #include <linux/slab.h>
11 #include <linux/taskstats.h>
12 #include <linux/time.h>
13 #include <linux/sysctl.h>
14 #include <linux/delayacct.h>
15 #include <linux/module.h>
16
17 int delayacct_on __read_mostly = 1;     /* Delay accounting turned on/off */
18 EXPORT_SYMBOL_GPL(delayacct_on);
19 struct kmem_cache *delayacct_cache;
20
21 static int __init delayacct_setup_disable(char *str)
22 {
23         delayacct_on = 0;
24         return 1;
25 }
26 __setup("nodelayacct", delayacct_setup_disable);
27
28 void delayacct_init(void)
29 {
30         delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT);
31         delayacct_tsk_init(&init_task);
32 }
33
34 void __delayacct_tsk_init(struct task_struct *tsk)
35 {
36         tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL);
37         if (tsk->delays)
38                 raw_spin_lock_init(&tsk->delays->lock);
39 }
40
41 /*
42  * Finish delay accounting for a statistic using its timestamps (@start),
43  * accumalator (@total) and @count
44  */
45 static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total,
46                           u32 *count)
47 {
48         s64 ns = ktime_get_ns() - *start;
49         unsigned long flags;
50
51         if (ns > 0) {
52                 raw_spin_lock_irqsave(lock, flags);
53                 *total += ns;
54                 (*count)++;
55                 raw_spin_unlock_irqrestore(lock, flags);
56         }
57 }
58
59 void __delayacct_blkio_start(void)
60 {
61         current->delays->blkio_start = ktime_get_ns();
62 }
63
64 /*
65  * We cannot rely on the `current` macro, as we haven't yet switched back to
66  * the process being woken.
67  */
68 void __delayacct_blkio_end(struct task_struct *p)
69 {
70         struct task_delay_info *delays = p->delays;
71         u64 *total;
72         u32 *count;
73
74         if (p->delays->flags & DELAYACCT_PF_SWAPIN) {
75                 total = &delays->swapin_delay;
76                 count = &delays->swapin_count;
77         } else {
78                 total = &delays->blkio_delay;
79                 count = &delays->blkio_count;
80         }
81
82         delayacct_end(&delays->lock, &delays->blkio_start, total, count);
83 }
84
85 int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
86 {
87         u64 utime, stime, stimescaled, utimescaled;
88         unsigned long long t2, t3;
89         unsigned long flags, t1;
90         s64 tmp;
91
92         task_cputime(tsk, &utime, &stime);
93         tmp = (s64)d->cpu_run_real_total;
94         tmp += utime + stime;
95         d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
96
97         task_cputime_scaled(tsk, &utimescaled, &stimescaled);
98         tmp = (s64)d->cpu_scaled_run_real_total;
99         tmp += utimescaled + stimescaled;
100         d->cpu_scaled_run_real_total =
101                 (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;
102
103         /*
104          * No locking available for sched_info (and too expensive to add one)
105          * Mitigate by taking snapshot of values
106          */
107         t1 = tsk->sched_info.pcount;
108         t2 = tsk->sched_info.run_delay;
109         t3 = tsk->se.sum_exec_runtime;
110
111         d->cpu_count += t1;
112
113         tmp = (s64)d->cpu_delay_total + t2;
114         d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp;
115
116         tmp = (s64)d->cpu_run_virtual_total + t3;
117         d->cpu_run_virtual_total =
118                 (tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp;
119
120         /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */
121
122         raw_spin_lock_irqsave(&tsk->delays->lock, flags);
123         tmp = d->blkio_delay_total + tsk->delays->blkio_delay;
124         d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp;
125         tmp = d->swapin_delay_total + tsk->delays->swapin_delay;
126         d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp;
127         tmp = d->freepages_delay_total + tsk->delays->freepages_delay;
128         d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp;
129         tmp = d->thrashing_delay_total + tsk->delays->thrashing_delay;
130         d->thrashing_delay_total = (tmp < d->thrashing_delay_total) ? 0 : tmp;
131         d->blkio_count += tsk->delays->blkio_count;
132         d->swapin_count += tsk->delays->swapin_count;
133         d->freepages_count += tsk->delays->freepages_count;
134         d->thrashing_count += tsk->delays->thrashing_count;
135         raw_spin_unlock_irqrestore(&tsk->delays->lock, flags);
136
137         return 0;
138 }
139
140 __u64 __delayacct_blkio_ticks(struct task_struct *tsk)
141 {
142         __u64 ret;
143         unsigned long flags;
144
145         raw_spin_lock_irqsave(&tsk->delays->lock, flags);
146         ret = nsec_to_clock_t(tsk->delays->blkio_delay +
147                                 tsk->delays->swapin_delay);
148         raw_spin_unlock_irqrestore(&tsk->delays->lock, flags);
149         return ret;
150 }
151
152 void __delayacct_freepages_start(void)
153 {
154         current->delays->freepages_start = ktime_get_ns();
155 }
156
157 void __delayacct_freepages_end(void)
158 {
159         delayacct_end(
160                 &current->delays->lock,
161                 &current->delays->freepages_start,
162                 &current->delays->freepages_delay,
163                 &current->delays->freepages_count);
164 }
165
166 void __delayacct_thrashing_start(void)
167 {
168         current->delays->thrashing_start = ktime_get_ns();
169 }
170
171 void __delayacct_thrashing_end(void)
172 {
173         delayacct_end(&current->delays->lock,
174                       &current->delays->thrashing_start,
175                       &current->delays->thrashing_delay,
176                       &current->delays->thrashing_count);
177 }