From 6f44993fe1d7b2b097f6ac60cd5835c6f5ca0874 Mon Sep 17 00:00:00 2001 From: Shailabh Nagar Date: Fri, 14 Jul 2006 00:24:41 -0700 Subject: [PATCH] per-task-delay-accounting: delay accounting usage of taskstats interface Usage of taskstats interface by delay accounting. 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 | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++- kernel/taskstats.c | 16 +++++++++----- 2 files changed, 72 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/delayacct.c b/kernel/delayacct.c index 3546b0800f9..1be274a462c 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -41,6 +41,10 @@ void delayacct_init(void) void __delayacct_tsk_init(struct task_struct *tsk) { + spin_lock_init(&tsk->delays_lock); + /* No need to acquire tsk->delays_lock for allocation here unless + __delayacct_tsk_init called after tsk is attached to tasklist + */ tsk->delays = kmem_cache_zalloc(delayacct_cache, SLAB_KERNEL); if (tsk->delays) spin_lock_init(&tsk->delays->lock); @@ -48,8 +52,11 @@ void __delayacct_tsk_init(struct task_struct *tsk) void __delayacct_tsk_exit(struct task_struct *tsk) { - kmem_cache_free(delayacct_cache, tsk->delays); + struct task_delay_info *delays = tsk->delays; + spin_lock(&tsk->delays_lock); tsk->delays = NULL; + spin_unlock(&tsk->delays_lock); + kmem_cache_free(delayacct_cache, delays); } /* @@ -104,3 +111,56 @@ void __delayacct_blkio_end(void) ¤t->delays->blkio_delay, ¤t->delays->blkio_count); } + +int __delayacct_add_tsk(struct taskstats *d, struct task_struct *tsk) +{ + s64 tmp; + struct timespec ts; + unsigned long t1,t2,t3; + + spin_lock(&tsk->delays_lock); + + /* 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; + + jiffies_to_timespec(t2, &ts); + tmp = (s64)d->cpu_delay_total + timespec_to_ns(&ts); + d->cpu_delay_total = (tmp < (s64)d->cpu_delay_total) ? 0 : tmp; + + tmp = (s64)d->cpu_run_virtual_total + (s64)jiffies_to_usecs(t3) * 1000; + 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(&tsk->delays->lock); + 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(&tsk->delays->lock); + +done: + spin_unlock(&tsk->delays_lock); + return 0; +} diff --git a/kernel/taskstats.c b/kernel/taskstats.c index 82ec9137d90..ea9506de3b8 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -18,13 +18,13 @@ #include #include +#include #include #include static DEFINE_PER_CPU(__u32, taskstats_seqnum) = { 0 }; static int family_registered; kmem_cache_t *taskstats_cache; -static DEFINE_MUTEX(taskstats_exit_mutex); static struct genl_family family = { .id = GENL_ID_GENERATE, @@ -120,7 +120,10 @@ static int fill_pid(pid_t pid, struct task_struct *pidtsk, * goto err; */ -err: + rc = delayacct_add_tsk(stats, tsk); + stats->version = TASKSTATS_VERSION; + + /* Define err: label here if needed */ put_task_struct(tsk); return rc; @@ -152,8 +155,14 @@ static int fill_tgid(pid_t tgid, struct task_struct *tgidtsk, * break; */ + rc = delayacct_add_tsk(stats, tsk); + if (rc) + break; + } while_each_thread(first, tsk); read_unlock(&tasklist_lock); + stats->version = TASKSTATS_VERSION; + /* * Accounting subsytems can also add calls here if they don't @@ -233,8 +242,6 @@ void taskstats_exit_send(struct task_struct *tsk, struct taskstats *tidstats, if (!family_registered || !tidstats) return; - mutex_lock(&taskstats_exit_mutex); - is_thread_group = !thread_group_empty(tsk); rc = 0; @@ -292,7 +299,6 @@ nla_put_failure: err_skb: nlmsg_free(rep_skb); ret: - mutex_unlock(&taskstats_exit_mutex); return; } -- cgit v1.2.3