From ca74e92b4698276b6696f15a801759f50944f387 Mon Sep 17 00:00:00 2001 From: Shailabh Nagar Date: Fri, 14 Jul 2006 00:24:36 -0700 Subject: [PATCH] per-task-delay-accounting: setup Initialization code related to collection of per-task "delay" statistics which measure how long it had to wait for cpu, sync block io, swapping etc. The collection of statistics and the interface are in other patches. This patch sets up the data structures and allows the statistics collection to be disabled through a kernel boot parameter. Signed-off-by: Shailabh Nagar Signed-off-by: Balbir Singh Cc: Jes Sorensen Cc: Peter Chubb Cc: Erich Focht Cc: Levent Serinol Cc: Jay Lan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/delayacct.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 kernel/delayacct.c (limited to 'kernel/delayacct.c') diff --git a/kernel/delayacct.c b/kernel/delayacct.c new file mode 100644 index 00000000000..fbf7f228495 --- /dev/null +++ b/kernel/delayacct.c @@ -0,0 +1,87 @@ +/* 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 +#include +#include +#include +#include + +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); +} + -- cgit v1.2.3