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Shailabh Nagarca74e922006-07-14 00:24:36 -07001/* 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>
Alexey Dobriyan6952b612009-09-18 23:55:55 +040018#include <linux/taskstats.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070019#include <linux/time.h>
20#include <linux/sysctl.h>
21#include <linux/delayacct.h>
Glauber Costac9aaa892011-07-11 15:28:14 -040022#include <linux/module.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070023
Shailabh Nagar163ecdf2006-07-30 03:03:11 -070024int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */
Glauber Costac9aaa892011-07-11 15:28:14 -040025EXPORT_SYMBOL_GPL(delayacct_on);
Christoph Lametere18b8902006-12-06 20:33:20 -080026struct kmem_cache *delayacct_cache;
Shailabh Nagarca74e922006-07-14 00:24:36 -070027
Shailabh Nagar163ecdf2006-07-30 03:03:11 -070028static int __init delayacct_setup_disable(char *str)
Shailabh Nagarca74e922006-07-14 00:24:36 -070029{
Shailabh Nagar163ecdf2006-07-30 03:03:11 -070030 delayacct_on = 0;
Shailabh Nagarca74e922006-07-14 00:24:36 -070031 return 1;
32}
Shailabh Nagar163ecdf2006-07-30 03:03:11 -070033__setup("nodelayacct", delayacct_setup_disable);
Shailabh Nagarca74e922006-07-14 00:24:36 -070034
35void delayacct_init(void)
36{
Vladimir Davydov5d097052016-01-14 15:18:21 -080037 delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT);
Shailabh Nagarca74e922006-07-14 00:24:36 -070038 delayacct_tsk_init(&init_task);
39}
40
41void __delayacct_tsk_init(struct task_struct *tsk)
42{
Christoph Lametere94b1762006-12-06 20:33:17 -080043 tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL);
Shailabh Nagarca74e922006-07-14 00:24:36 -070044 if (tsk->delays)
45 spin_lock_init(&tsk->delays->lock);
46}
47
Shailabh Nagarca74e922006-07-14 00:24:36 -070048/*
Thomas Gleixner9667a232014-07-16 21:04:35 +000049 * Finish delay accounting for a statistic using its timestamps (@start),
50 * accumalator (@total) and @count
Shailabh Nagarca74e922006-07-14 00:24:36 -070051 */
Thomas Gleixner9667a232014-07-16 21:04:35 +000052static void delayacct_end(u64 *start, u64 *total, u32 *count)
Shailabh Nagarca74e922006-07-14 00:24:36 -070053{
Thomas Gleixner9667a232014-07-16 21:04:35 +000054 s64 ns = ktime_get_ns() - *start;
Peter Zijlstra64efade2006-11-05 23:52:10 -080055 unsigned long flags;
Shailabh Nagarca74e922006-07-14 00:24:36 -070056
Thomas Gleixner9667a232014-07-16 21:04:35 +000057 if (ns > 0) {
58 spin_lock_irqsave(&current->delays->lock, flags);
59 *total += ns;
60 (*count)++;
61 spin_unlock_irqrestore(&current->delays->lock, flags);
62 }
Shailabh Nagarca74e922006-07-14 00:24:36 -070063}
64
Shailabh Nagar0ff92242006-07-14 00:24:37 -070065void __delayacct_blkio_start(void)
66{
Thomas Gleixner9667a232014-07-16 21:04:35 +000067 current->delays->blkio_start = ktime_get_ns();
Shailabh Nagar0ff92242006-07-14 00:24:37 -070068}
69
70void __delayacct_blkio_end(void)
71{
72 if (current->delays->flags & DELAYACCT_PF_SWAPIN)
73 /* Swapin block I/O */
74 delayacct_end(&current->delays->blkio_start,
Shailabh Nagar0ff92242006-07-14 00:24:37 -070075 &current->delays->swapin_delay,
76 &current->delays->swapin_count);
77 else /* Other block I/O */
78 delayacct_end(&current->delays->blkio_start,
Shailabh Nagar0ff92242006-07-14 00:24:37 -070079 &current->delays->blkio_delay,
80 &current->delays->blkio_count);
81}
Shailabh Nagar6f449932006-07-14 00:24:41 -070082
83int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
84{
Frederic Weisbecker6fac4822012-11-13 14:20:55 +010085 cputime_t utime, stime, stimescaled, utimescaled;
Thomas Gleixner68f6783d2014-07-16 21:04:37 +000086 unsigned long long t2, t3;
87 unsigned long flags, t1;
88 s64 tmp;
Shailabh Nagar6f449932006-07-14 00:24:41 -070089
Frederic Weisbecker6fac4822012-11-13 14:20:55 +010090 task_cputime(tsk, &utime, &stime);
Thomas Gleixner68f6783d2014-07-16 21:04:37 +000091 tmp = (s64)d->cpu_run_real_total;
92 tmp += cputime_to_nsecs(utime + stime);
Shailabh Nagar6f449932006-07-14 00:24:41 -070093 d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
94
Frederic Weisbecker6fac4822012-11-13 14:20:55 +010095 task_cputime_scaled(tsk, &utimescaled, &stimescaled);
Thomas Gleixner68f6783d2014-07-16 21:04:37 +000096 tmp = (s64)d->cpu_scaled_run_real_total;
97 tmp += cputime_to_nsecs(utimescaled + stimescaled);
Michael Neulingc66f08b2007-10-18 03:06:34 -070098 d->cpu_scaled_run_real_total =
99 (tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;
100
Shailabh Nagar6f449932006-07-14 00:24:41 -0700101 /*
102 * No locking available for sched_info (and too expensive to add one)
103 * Mitigate by taking snapshot of values
104 */
Ingo Molnar2d723762007-10-15 17:00:12 +0200105 t1 = tsk->sched_info.pcount;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700106 t2 = tsk->sched_info.run_delay;
Ken Chen9c2c4802008-12-16 23:41:22 -0800107 t3 = tsk->se.sum_exec_runtime;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700108
109 d->cpu_count += t1;
110
Balbir Singh172ba842007-07-09 18:52:00 +0200111 tmp = (s64)d->cpu_delay_total + t2;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700112 d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp;
113
Balbir Singh172ba842007-07-09 18:52:00 +0200114 tmp = (s64)d->cpu_run_virtual_total + t3;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700115 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
Peter Zijlstra64efade2006-11-05 23:52:10 -0800120 spin_lock_irqsave(&tsk->delays->lock, flags);
Shailabh Nagar6f449932006-07-14 00:24:41 -0700121 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;
Keika Kobayashi016ae212008-07-25 01:48:53 -0700125 tmp = d->freepages_delay_total + tsk->delays->freepages_delay;
126 d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp;
Shailabh Nagar6f449932006-07-14 00:24:41 -0700127 d->blkio_count += tsk->delays->blkio_count;
128 d->swapin_count += tsk->delays->swapin_count;
Keika Kobayashi016ae212008-07-25 01:48:53 -0700129 d->freepages_count += tsk->delays->freepages_count;
Peter Zijlstra64efade2006-11-05 23:52:10 -0800130 spin_unlock_irqrestore(&tsk->delays->lock, flags);
Shailabh Nagar6f449932006-07-14 00:24:41 -0700131
Shailabh Nagar6f449932006-07-14 00:24:41 -0700132 return 0;
133}
Shailabh Nagar25890452006-07-14 00:24:43 -0700134
135__u64 __delayacct_blkio_ticks(struct task_struct *tsk)
136{
137 __u64 ret;
Peter Zijlstra64efade2006-11-05 23:52:10 -0800138 unsigned long flags;
Shailabh Nagar25890452006-07-14 00:24:43 -0700139
Peter Zijlstra64efade2006-11-05 23:52:10 -0800140 spin_lock_irqsave(&tsk->delays->lock, flags);
Shailabh Nagar25890452006-07-14 00:24:43 -0700141 ret = nsec_to_clock_t(tsk->delays->blkio_delay +
142 tsk->delays->swapin_delay);
Peter Zijlstra64efade2006-11-05 23:52:10 -0800143 spin_unlock_irqrestore(&tsk->delays->lock, flags);
Shailabh Nagar25890452006-07-14 00:24:43 -0700144 return ret;
145}
146
Keika Kobayashi873b4772008-07-25 01:48:52 -0700147void __delayacct_freepages_start(void)
148{
Thomas Gleixner9667a232014-07-16 21:04:35 +0000149 current->delays->freepages_start = ktime_get_ns();
Keika Kobayashi873b4772008-07-25 01:48:52 -0700150}
151
152void __delayacct_freepages_end(void)
153{
154 delayacct_end(&current->delays->freepages_start,
Keika Kobayashi873b4772008-07-25 01:48:52 -0700155 &current->delays->freepages_delay,
156 &current->delays->freepages_count);
157}
158