123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165 |
- /* 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 = 1; /* Delay accounting turned on/off */
- struct kmem_cache *delayacct_cache;
- static int __init delayacct_setup_disable(char *str)
- {
- delayacct_on = 0;
- return 1;
- }
- __setup("nodelayacct", delayacct_setup_disable);
- 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, GFP_KERNEL);
- if (tsk->delays)
- spin_lock_init(&tsk->delays->lock);
- }
- /*
- * 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;
- unsigned long flags;
- do_posix_clock_monotonic_gettime(end);
- ts = timespec_sub(*end, *start);
- ns = timespec_to_ns(&ts);
- if (ns < 0)
- return;
- spin_lock_irqsave(¤t->delays->lock, flags);
- *total += ns;
- (*count)++;
- spin_unlock_irqrestore(¤t->delays->lock, flags);
- }
- 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);
- }
- int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
- {
- s64 tmp;
- unsigned long t1;
- unsigned long long t2,t3;
- unsigned long flags;
- struct timespec ts;
- /* Though tsk->delays accessed later, early exit avoids
- * unnecessary returning of other data
- */
- if (!tsk->delays)
- goto done;
- tmp = (s64)d->cpu_run_real_total;
- cputime_to_timespec(tsk->utime + tsk->stime, &ts);
- tmp += timespec_to_ns(&ts);
- d->cpu_run_real_total = (tmp < (s64)d->cpu_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.pcnt;
- t2 = tsk->sched_info.run_delay;
- t3 = tsk->sched_info.cpu_time;
- 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;
- /* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */
- 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;
- d->blkio_count += tsk->delays->blkio_count;
- d->swapin_count += tsk->delays->swapin_count;
- spin_unlock_irqrestore(&tsk->delays->lock, flags);
- done:
- return 0;
- }
- __u64 __delayacct_blkio_ticks(struct task_struct *tsk)
- {
- __u64 ret;
- unsigned long flags;
- spin_lock_irqsave(&tsk->delays->lock, flags);
- ret = nsec_to_clock_t(tsk->delays->blkio_delay +
- tsk->delays->swapin_delay);
- spin_unlock_irqrestore(&tsk->delays->lock, flags);
- return ret;
- }
|