0a31bd5f2b
This patch provides a new macro
KMEM_CACHE(<struct>, <flags>)
to simplify slab creation. KMEM_CACHE creates a slab with the name of the
struct, with the size of the struct and with the alignment of the struct.
Additional slab flags may be specified if necessary.
Example
struct test_slab {
int a,b,c;
struct list_head;
} __cacheline_aligned_in_smp;
test_slab_cache = KMEM_CACHE(test_slab, SLAB_PANIC)
will create a new slab named "test_slab" of the size sizeof(struct
test_slab) and aligned to the alignment of test slab. If it fails then we
panic.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
162 lines
4.3 KiB
C
162 lines
4.3 KiB
C
/* delayacct.c - per-task delay accounting
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*
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* Copyright (C) Shailabh Nagar, IBM Corp. 2006
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it would be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*/
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/time.h>
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#include <linux/sysctl.h>
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#include <linux/delayacct.h>
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int delayacct_on __read_mostly = 1; /* Delay accounting turned on/off */
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struct kmem_cache *delayacct_cache;
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static int __init delayacct_setup_disable(char *str)
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{
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delayacct_on = 0;
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return 1;
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}
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__setup("nodelayacct", delayacct_setup_disable);
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void delayacct_init(void)
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{
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delayacct_cache = KMEM_CACHE(task_delay_info, SLAB_PANIC);
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delayacct_tsk_init(&init_task);
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}
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void __delayacct_tsk_init(struct task_struct *tsk)
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{
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tsk->delays = kmem_cache_zalloc(delayacct_cache, GFP_KERNEL);
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if (tsk->delays)
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spin_lock_init(&tsk->delays->lock);
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}
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/*
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* Start accounting for a delay statistic using
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* its starting timestamp (@start)
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*/
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static inline void delayacct_start(struct timespec *start)
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{
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do_posix_clock_monotonic_gettime(start);
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}
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/*
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* Finish delay accounting for a statistic using
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* its timestamps (@start, @end), accumalator (@total) and @count
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*/
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static void delayacct_end(struct timespec *start, struct timespec *end,
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u64 *total, u32 *count)
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{
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struct timespec ts;
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s64 ns;
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unsigned long flags;
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do_posix_clock_monotonic_gettime(end);
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ts = timespec_sub(*end, *start);
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ns = timespec_to_ns(&ts);
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if (ns < 0)
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return;
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spin_lock_irqsave(¤t->delays->lock, flags);
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*total += ns;
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(*count)++;
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spin_unlock_irqrestore(¤t->delays->lock, flags);
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}
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void __delayacct_blkio_start(void)
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{
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delayacct_start(¤t->delays->blkio_start);
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}
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void __delayacct_blkio_end(void)
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{
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if (current->delays->flags & DELAYACCT_PF_SWAPIN)
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/* Swapin block I/O */
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delayacct_end(¤t->delays->blkio_start,
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¤t->delays->blkio_end,
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¤t->delays->swapin_delay,
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¤t->delays->swapin_count);
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else /* Other block I/O */
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delayacct_end(¤t->delays->blkio_start,
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¤t->delays->blkio_end,
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¤t->delays->blkio_delay,
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¤t->delays->blkio_count);
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}
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int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk)
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{
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s64 tmp;
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struct timespec ts;
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unsigned long t1,t2,t3;
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unsigned long flags;
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/* Though tsk->delays accessed later, early exit avoids
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* unnecessary returning of other data
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*/
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if (!tsk->delays)
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goto done;
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tmp = (s64)d->cpu_run_real_total;
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cputime_to_timespec(tsk->utime + tsk->stime, &ts);
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tmp += timespec_to_ns(&ts);
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d->cpu_run_real_total = (tmp < (s64)d->cpu_run_real_total) ? 0 : tmp;
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/*
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* No locking available for sched_info (and too expensive to add one)
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* Mitigate by taking snapshot of values
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*/
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t1 = tsk->sched_info.pcnt;
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t2 = tsk->sched_info.run_delay;
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t3 = tsk->sched_info.cpu_time;
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d->cpu_count += t1;
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jiffies_to_timespec(t2, &ts);
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tmp = (s64)d->cpu_delay_total + timespec_to_ns(&ts);
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d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp;
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tmp = (s64)d->cpu_run_virtual_total + (s64)jiffies_to_usecs(t3) * 1000;
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d->cpu_run_virtual_total =
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(tmp < (s64)d->cpu_run_virtual_total) ? 0 : tmp;
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/* zero XXX_total, non-zero XXX_count implies XXX stat overflowed */
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spin_lock_irqsave(&tsk->delays->lock, flags);
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tmp = d->blkio_delay_total + tsk->delays->blkio_delay;
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d->blkio_delay_total = (tmp < d->blkio_delay_total) ? 0 : tmp;
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tmp = d->swapin_delay_total + tsk->delays->swapin_delay;
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d->swapin_delay_total = (tmp < d->swapin_delay_total) ? 0 : tmp;
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d->blkio_count += tsk->delays->blkio_count;
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d->swapin_count += tsk->delays->swapin_count;
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spin_unlock_irqrestore(&tsk->delays->lock, flags);
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done:
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return 0;
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}
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__u64 __delayacct_blkio_ticks(struct task_struct *tsk)
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{
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__u64 ret;
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unsigned long flags;
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spin_lock_irqsave(&tsk->delays->lock, flags);
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ret = nsec_to_clock_t(tsk->delays->blkio_delay +
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tsk->delays->swapin_delay);
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spin_unlock_irqrestore(&tsk->delays->lock, flags);
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return ret;
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}
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