reweight_eevdf() needs the latest V to do accurate calculation for new
ve and vd. So update V unconditionally when se is runnable.

Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
Suggested-by: Abel Wu <wuyun.abel@bytedance.com>
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
---
 kernel/sched/fair.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 03be0d1330a6..5551ce2af73e 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3790,9 +3790,8 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
 
 	if (se->on_rq) {
 		/* commit outstanding execution time */
-		if (curr)
-			update_curr(cfs_rq);
-		else
+		update_curr(cfs_rq);
+		if (!curr)
 			__dequeue_entity(cfs_rq, se);
 		update_load_sub(&cfs_rq->load, se->load.weight);
 	}
-- 
2.39.3

On 3/6/24 10:21 AM, Tianchen Ding Wrote:
> reweight_eevdf() needs the latest V to do accurate calculation for new
> ve and vd. So update V unconditionally when se is runnable.
> 
> Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
> Suggested-by: Abel Wu <wuyun.abel@bytedance.com>
> Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
> ---
>   kernel/sched/fair.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 03be0d1330a6..5551ce2af73e 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -3790,9 +3790,8 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
>   
>   	if (se->on_rq) {
>   		/* commit outstanding execution time */
> -		if (curr)
> -			update_curr(cfs_rq);
> -		else
> +		update_curr(cfs_rq);
> +		if (!curr)
>   			__dequeue_entity(cfs_rq, se);
>   		update_load_sub(&cfs_rq->load, se->load.weight);
>   	}

Reviewed-by: Abel Wu <wuyun.abel@bytedance.com>

Thanks!

The following commit has been merged into the sched/urgent branch of tip:

Commit-ID:     11b1b8bc2b98e21ddf47e08b56c21502c685b2c3
Gitweb:        https://git.kernel.org/tip/11b1b8bc2b98e21ddf47e08b56c21502c685b2c3
Author:        Tianchen Ding <dtcccc@linux.alibaba.com>
AuthorDate:    Wed, 06 Mar 2024 10:21:32 +08:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 22 Apr 2024 13:01:26 +02:00

sched/eevdf: Always update V if se->on_rq when reweighting

reweight_eevdf() needs the latest V to do accurate calculation for new
ve and vd. So update V unconditionally when se is runnable.

Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
Suggested-by: Abel Wu <wuyun.abel@bytedance.com>
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Abel Wu <wuyun.abel@bytedance.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Link: https://lore.kernel.org/r/20240306022133.81008-2-dtcccc@linux.alibaba.com
---
 kernel/sched/fair.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 03be0d1..5551ce2 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3790,9 +3790,8 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
 
 	if (se->on_rq) {
 		/* commit outstanding execution time */
-		if (curr)
-			update_curr(cfs_rq);
-		else
+		update_curr(cfs_rq);
+		if (!curr)
 			__dequeue_entity(cfs_rq, se);
 		update_load_sub(&cfs_rq->load, se->load.weight);
 	}