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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
parent286100a6cf1c1f692e5f81d14b364ff12b7662f5 (diff)
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>
-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 734f6d8f6ed..df5b24ee80b 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 9e5de098d47..4b5e24cf2f4 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 45ff4e9411e..72e25c7a3a1 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);
}