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* [PATCH] sched/fair: Optimize vlag entity placement
@ 2024-07-04  9:23 Fernand Sieber
  2024-07-04 12:20 ` Metin Kaya
  0 siblings, 1 reply; 2+ messages in thread
From: Fernand Sieber @ 2024-07-04  9:23 UTC (permalink / raw)
  Cc: linux-kernel, Fernand Sieber, Ingo Molnar, Peter Zijlstra,
	Juri Lelli, Vincent Guittot

Optimize for common path when placing an entity with no lag.
Since adjusting a zero lag is always going to produce a zero lag regardless
of the local load, don't bother about calaculating the adjusting factor.

Signed-off-by: Fernand Sieber <sieberf@amazon.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
---
 kernel/sched/fair.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8a5b1ae0aa55..e78272c87274 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5190,7 +5190,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
 	 *
 	 * EEVDF: placement strategy #1 / #2
 	 */
-	if (sched_feat(PLACE_LAG) && cfs_rq->nr_running) {
+	if (se->vlag && sched_feat(PLACE_LAG) && cfs_rq->nr_running) {
 		struct sched_entity *curr = cfs_rq->curr;
 		unsigned long load;
 
-- 
2.40.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] sched/fair: Optimize vlag entity placement
  2024-07-04  9:23 [PATCH] sched/fair: Optimize vlag entity placement Fernand Sieber
@ 2024-07-04 12:20 ` Metin Kaya
  0 siblings, 0 replies; 2+ messages in thread
From: Metin Kaya @ 2024-07-04 12:20 UTC (permalink / raw)
  To: Fernand Sieber
  Cc: linux-kernel, Ingo Molnar, Peter Zijlstra, Juri Lelli,
	Vincent Guittot

On 04/07/2024 10:23 am, Fernand Sieber wrote:
> Optimize for common path when placing an entity with no lag.
> Since adjusting a zero lag is always going to produce a zero lag regardless
> of the local load, don't bother about calaculating the adjusting factor.
                                         calculating

> 
> Signed-off-by: Fernand Sieber <sieberf@amazon.com>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Juri Lelli <juri.lelli@redhat.com>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> ---
>   kernel/sched/fair.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 8a5b1ae0aa55..e78272c87274 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -5190,7 +5190,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
>   	 *
>   	 * EEVDF: placement strategy #1 / #2
>   	 */
> -	if (sched_feat(PLACE_LAG) && cfs_rq->nr_running) {
> +	if (se->vlag && sched_feat(PLACE_LAG) && cfs_rq->nr_running) {
>   		struct sched_entity *curr = cfs_rq->curr;
>   		unsigned long load;
>   

Thanks,


^ permalink raw reply	[flat|nested] 2+ messages in thread

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