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authorArjan van de Ven <arjan@linux.intel.com>2008-01-25 21:08:35 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-25 21:08:35 +0100
commit6d082592b62689fb91578d0338d04a9f50991990 (patch)
treefacef621798752724be64c3ded31a3c3fded1643
parentsched, futex: detach sched.h and futex.h (diff)
downloadlinux-dev-6d082592b62689fb91578d0338d04a9f50991990.tar.xz
linux-dev-6d082592b62689fb91578d0338d04a9f50991990.zip
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 <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to '')
-rw-r--r--include/linux/sched.h2
-rw-r--r--kernel/sched_debug.c4
-rw-r--r--kernel/sched_fair.c3
3 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 734f6d8f6ed5..df5b24ee80b3 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 9e5de098d471..4b5e24cf2f4a 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 45ff4e9411e0..72e25c7a3a18 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);
}