2006-07-14 07:24:36 +00:00
|
|
|
/* delayacct.c - per-task delay accounting
|
|
|
|
*
|
|
|
|
* Copyright (C) Shailabh Nagar, IBM Corp. 2006
|
|
|
|
*
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
* it under the terms of the GNU General Public License as published by
|
|
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
|
|
* (at your option) any later version.
|
|
|
|
*
|
|
|
|
* This program is distributed in the hope that it would be useful, but
|
|
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
|
|
|
|
* the GNU General Public License for more details.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <linux/sched.h>
|
|
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/time.h>
|
|
|
|
#include <linux/sysctl.h>
|
|
|
|
#include <linux/delayacct.h>
|
|
|
|
|
|
|
|
int delayacct_on __read_mostly; /* Delay accounting turned on/off */
|
|
|
|
kmem_cache_t *delayacct_cache;
|
|
|
|
|
|
|
|
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_create("delayacct_cache",
|
|
|
|
sizeof(struct task_delay_info),
|
|
|
|
0,
|
|
|
|
SLAB_PANIC,
|
|
|
|
NULL, NULL);
|
|
|
|
delayacct_tsk_init(&init_task);
|
|
|
|
}
|
|
|
|
|
|
|
|
void __delayacct_tsk_init(struct task_struct *tsk)
|
|
|
|
{
|
|
|
|
tsk->delays = kmem_cache_zalloc(delayacct_cache, SLAB_KERNEL);
|
|
|
|
if (tsk->delays)
|
|
|
|
spin_lock_init(&tsk->delays->lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
void __delayacct_tsk_exit(struct task_struct *tsk)
|
|
|
|
{
|
|
|
|
kmem_cache_free(delayacct_cache, tsk->delays);
|
|
|
|
tsk->delays = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Start accounting for a delay statistic using
|
|
|
|
* its starting timestamp (@start)
|
|
|
|
*/
|
|
|
|
|
|
|
|
static inline void delayacct_start(struct timespec *start)
|
|
|
|
{
|
|
|
|
do_posix_clock_monotonic_gettime(start);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Finish delay accounting for a statistic using
|
|
|
|
* its timestamps (@start, @end), accumalator (@total) and @count
|
|
|
|
*/
|
|
|
|
|
|
|
|
static void delayacct_end(struct timespec *start, struct timespec *end,
|
|
|
|
u64 *total, u32 *count)
|
|
|
|
{
|
|
|
|
struct timespec ts;
|
|
|
|
s64 ns;
|
|
|
|
|
|
|
|
do_posix_clock_monotonic_gettime(end);
|
|
|
|
ts = timespec_sub(*end, *start);
|
|
|
|
ns = timespec_to_ns(&ts);
|
|
|
|
if (ns < 0)
|
|
|
|
return;
|
|
|
|
|
|
|
|
spin_lock(¤t->delays->lock);
|
|
|
|
*total += ns;
|
|
|
|
(*count)++;
|
|
|
|
spin_unlock(¤t->delays->lock);
|
|
|
|
}
|
|
|
|
|
2006-07-14 07:24:37 +00:00
|
|
|
void __delayacct_blkio_start(void)
|
|
|
|
{
|
|
|
|
delayacct_start(¤t->delays->blkio_start);
|
|
|
|
}
|
|
|
|
|
|
|
|
void __delayacct_blkio_end(void)
|
|
|
|
{
|
|
|
|
if (current->delays->flags & DELAYACCT_PF_SWAPIN)
|
|
|
|
/* Swapin block I/O */
|
|
|
|
delayacct_end(¤t->delays->blkio_start,
|
|
|
|
¤t->delays->blkio_end,
|
|
|
|
¤t->delays->swapin_delay,
|
|
|
|
¤t->delays->swapin_count);
|
|
|
|
else /* Other block I/O */
|
|
|
|
delayacct_end(¤t->delays->blkio_start,
|
|
|
|
¤t->delays->blkio_end,
|
|
|
|
¤t->delays->blkio_delay,
|
|
|
|
¤t->delays->blkio_count);
|
|
|
|
}
|