From 6d082592b62689fb91578d0338d04a9f50991990 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Fri, 25 Jan 2008 21:08:35 +0100 Subject: [PATCH] sched: keep total / count stats in addition to the max for Right now, the linux kernel (with scheduler statistics enabled) keeps track of the maximum time a process is waiting to be scheduled. While the maximum is a very useful metric, tracking average and total is equally useful (at least for latencytop) to figure out the accumulated effect of scheduler delays. The accumulated effect is important to judge the performance impact of scheduler tuning/behavior. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar --- include/linux/sched.h | 2 ++ kernel/sched_debug.c | 4 ++++ kernel/sched_fair.c | 3 +++ 3 files changed, 9 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index 734f6d8..df5b24e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -895,6 +895,8 @@ struct sched_entity { #ifdef CONFIG_SCHEDSTATS u64 wait_start; u64 wait_max; + u64 wait_count; + u64 wait_sum; u64 sleep_start; u64 sleep_max; diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 9e5de09..4b5e24c 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -300,6 +300,8 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) PN(se.exec_max); PN(se.slice_max); PN(se.wait_max); + PN(se.wait_sum); + P(se.wait_count); P(sched_info.bkl_count); P(se.nr_migrations); P(se.nr_migrations_cold); @@ -367,6 +369,8 @@ void proc_sched_set_task(struct task_struct *p) { #ifdef CONFIG_SCHEDSTATS p->se.wait_max = 0; + p->se.wait_sum = 0; + p->se.wait_count = 0; p->se.sleep_max = 0; p->se.sum_sleep_runtime = 0; p->se.block_max = 0; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 45ff4e9..72e25c7 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -385,6 +385,9 @@ update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se) { schedstat_set(se->wait_max, max(se->wait_max, rq_of(cfs_rq)->clock - se->wait_start)); + schedstat_set(se->wait_count, se->wait_count + 1); + schedstat_set(se->wait_sum, se->wait_sum + + rq_of(cfs_rq)->clock - se->wait_start); schedstat_set(se->wait_start, 0); } -- 2.7.4