mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-16 08:44:21 +08:00
0cd7c741f0
Just like sched_schedstats, allow runtime enabling (and disabling) of delayacct. This is useful if one forgot to add the delayacct boot time option. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YJkhebGJAywaZowX@hirez.programming.kicks-ass.net
213 lines
5.4 KiB
C
213 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/* delayacct.c - per-task delay accounting
|
|
*
|
|
* Copyright (C) Shailabh Nagar, IBM Corp. 2006
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/sched/task.h>
|
|
#include <linux/sched/cputime.h>
|
|
#include <linux/sched/clock.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/taskstats.h>
|
|
#include <linux/sysctl.h>
|
|
#include <linux/delayacct.h>
|
|
#include <linux/module.h>
|
|
|
|
DEFINE_STATIC_KEY_FALSE(delayacct_key);
|
|
int delayacct_on __read_mostly; /* Delay accounting turned on/off */
|
|
struct kmem_cache *delayacct_cache;
|
|
|
|
static void set_delayacct(bool enabled)
|
|
{
|
|
if (enabled) {
|
|
static_branch_enable(&delayacct_key);
|
|
delayacct_on = 1;
|
|
} else {
|
|
delayacct_on = 0;
|
|
static_branch_disable(&delayacct_key);
|
|
}
|
|
}
|
|
|
|
static int __init delayacct_setup_enable(char *str)
|
|
{
|
|
delayacct_on = 1;
|
|
return 1;
|
|
}
|
|
__setup("delayacct", delayacct_setup_enable);
|
|
|
|
void delayacct_init(void)
|
|
{
|
|
delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC|SLAB_ACCOUNT);
|
|
delayacct_tsk_init(&init_task);
|
|
set_delayacct(delayacct_on);
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_SYSCTL
|
|
int sysctl_delayacct(struct ctl_table *table, int write, void *buffer,
|
|
size_t *lenp, loff_t *ppos)
|
|
{
|
|
int state = delayacct_on;
|
|
struct ctl_table t;
|
|
int err;
|
|
|
|
if (write && !capable(CAP_SYS_ADMIN))
|
|
return -EPERM;
|
|
|
|
t = *table;
|
|
t.data = &state;
|
|
err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
|
|
if (err < 0)
|
|
return err;
|
|
if (write)
|
|
set_delayacct(state);
|
|
return err;
|
|
}
|
|
#endif
|
|
|
|
void __delayacct_tsk_init(struct task_struct *tsk)
|
|
{
|
|
tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL);
|
|
if (tsk->delays)
|
|
raw_spin_lock_init(&tsk->delays->lock);
|
|
}
|
|
|
|
/*
|
|
* Finish delay accounting for a statistic using its timestamps (@start),
|
|
* accumalator (@total) and @count
|
|
*/
|
|
static void delayacct_end(raw_spinlock_t *lock, u64 *start, u64 *total, u32 *count)
|
|
{
|
|
s64 ns = local_clock() - *start;
|
|
unsigned long flags;
|
|
|
|
if (ns > 0) {
|
|
raw_spin_lock_irqsave(lock, flags);
|
|
*total += ns;
|
|
(*count)++;
|
|
raw_spin_unlock_irqrestore(lock, flags);
|
|
}
|
|
}
|
|
|
|
void __delayacct_blkio_start(void)
|
|
{
|
|
current->delays->blkio_start = local_clock();
|
|
}
|
|
|
|
/*
|
|
* We cannot rely on the `current` macro, as we haven't yet switched back to
|
|
* the process being woken.
|
|
*/
|
|
void __delayacct_blkio_end(struct task_struct *p)
|
|
{
|
|
struct task_delay_info *delays = p->delays;
|
|
u64 *total;
|
|
u32 *count;
|
|
|
|
if (p->delays->flags & DELAYACCT_PF_SWAPIN) {
|
|
total = &delays->swapin_delay;
|
|
count = &delays->swapin_count;
|
|
} else {
|
|
total = &delays->blkio_delay;
|
|
count = &delays->blkio_count;
|
|
}
|
|
|
|
delayacct_end(&delays->lock, &delays->blkio_start, total, count);
|
|
}
|
|
|
|
int delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
|
|
{
|
|
u64 utime, stime, stimescaled, utimescaled;
|
|
unsigned long long t2, t3;
|
|
unsigned long flags, t1;
|
|
s64 tmp;
|
|
|
|
task_cputime(tsk, &utime, &stime);
|
|
tmp = (s64)d->cpu_run_real_total;
|
|
tmp += utime + stime;
|
|
d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
|
|
|
|
task_cputime_scaled(tsk, &utimescaled, &stimescaled);
|
|
tmp = (s64)d->cpu_scaled_run_real_total;
|
|
tmp += utimescaled + stimescaled;
|
|
d->cpu_scaled_run_real_total =
|
|
(tmp < (s64)d->cpu_scaled_run_real_total) ? 0 : tmp;
|
|
|
|
/*
|
|
* No locking available for sched_info (and too expensive to add one)
|
|
* Mitigate by taking snapshot of values
|
|
*/
|
|
t1 = tsk->sched_info.pcount;
|
|
t2 = tsk->sched_info.run_delay;
|
|
t3 = tsk->se.sum_exec_runtime;
|
|
|
|
d->cpu_count += t1;
|
|
|
|
tmp = (s64)d->cpu_delay_total + t2;
|
|
d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp;
|
|
|
|
tmp = (s64)d->cpu_run_virtual_total + t3;
|
|
d->cpu_run_virtual_total =
|
|
(tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp;
|
|
|
|
if (!tsk->delays)
|
|
return 0;
|
|
|
|
/* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */
|
|
|
|
raw_spin_lock_irqsave(&tsk->delays->lock, flags);
|
|
tmp = d->blkio_delay_total + tsk->delays->blkio_delay;
|
|
d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp;
|
|
tmp = d->swapin_delay_total + tsk->delays->swapin_delay;
|
|
d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp;
|
|
tmp = d->freepages_delay_total + tsk->delays->freepages_delay;
|
|
d->freepages_delay_total = (tmp < d->freepages_delay_total) ? 0 : tmp;
|
|
tmp = d->thrashing_delay_total + tsk->delays->thrashing_delay;
|
|
d->thrashing_delay_total = (tmp < d->thrashing_delay_total) ? 0 : tmp;
|
|
d->blkio_count += tsk->delays->blkio_count;
|
|
d->swapin_count += tsk->delays->swapin_count;
|
|
d->freepages_count += tsk->delays->freepages_count;
|
|
d->thrashing_count += tsk->delays->thrashing_count;
|
|
raw_spin_unlock_irqrestore(&tsk->delays->lock, flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
__u64 __delayacct_blkio_ticks(struct task_struct *tsk)
|
|
{
|
|
__u64 ret;
|
|
unsigned long flags;
|
|
|
|
raw_spin_lock_irqsave(&tsk->delays->lock, flags);
|
|
ret = nsec_to_clock_t(tsk->delays->blkio_delay +
|
|
tsk->delays->swapin_delay);
|
|
raw_spin_unlock_irqrestore(&tsk->delays->lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
void __delayacct_freepages_start(void)
|
|
{
|
|
current->delays->freepages_start = local_clock();
|
|
}
|
|
|
|
void __delayacct_freepages_end(void)
|
|
{
|
|
delayacct_end(¤t->delays->lock,
|
|
¤t->delays->freepages_start,
|
|
¤t->delays->freepages_delay,
|
|
¤t->delays->freepages_count);
|
|
}
|
|
|
|
void __delayacct_thrashing_start(void)
|
|
{
|
|
current->delays->thrashing_start = local_clock();
|
|
}
|
|
|
|
void __delayacct_thrashing_end(void)
|
|
{
|
|
delayacct_end(¤t->delays->lock,
|
|
¤t->delays->thrashing_start,
|
|
¤t->delays->thrashing_delay,
|
|
¤t->delays->thrashing_count);
|
|
}
|