[PATCH] sched/deadline: Remove redundant code replenishing runtime

From: Byungchul Park
Date: Fri Feb 10 2017 - 04:27:26 EST


For a task passing its deadline while !rq, it will be replenished
in the following path because dl_se->deadline < rq_lock.

enqueue_dl_entity(ENQUEUE_WAKEUP)
update_dl_entity

Therefore, code replenishing it in the timer callback in the case is
unnecessary. This is not for enhancing performance but just for removing
a redundant code.

Signed-off-by: Byungchul Park <byungchul.park@xxxxxxx>
---
kernel/sched/deadline.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 27737f3..9c77696 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -624,10 +624,8 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
* We can be both throttled and !queued. Replenish the counter
* but do not enqueue -- wait for our wakeup to do that.
*/
- if (!task_on_rq_queued(p)) {
- replenish_dl_entity(dl_se, dl_se);
+ if (!task_on_rq_queued(p))
goto unlock;
- }

#ifdef CONFIG_SMP
if (unlikely(!rq->online)) {
--
1.9.1