[tip: sched/core] sched/fair: Update min_vruntime for reweight_entity() correctly

From: tip-bot2 for Yiwei Lin
Date: Wed Nov 29 2023 - 09:55:42 EST


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

Commit-ID: 5068d84054b766efe7c6202fc71b2350d1c326f1
Gitweb: https://git.kernel.org/tip/5068d84054b766efe7c6202fc71b2350d1c326f1
Author: Yiwei Lin <s921975628@xxxxxxxxx>
AuthorDate: Fri, 17 Nov 2023 16:01:06 +08:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Wed, 29 Nov 2023 15:43:52 +01:00

sched/fair: Update min_vruntime for reweight_entity() correctly

Since reweight_entity() may have chance to change the weight of
cfs_rq->curr entity, we should also update_min_vruntime() if
this is the case

Fixes: eab03c23c2a1 ("sched/eevdf: Fix vruntime adjustment on reweight")
Signed-off-by: Yiwei Lin <s921975628@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Abel Wu <wuyun.abel@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231117080106.12890-1-s921975628@xxxxxxxxx
---
kernel/sched/fair.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 34fe6e9..bcea3d5 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -3815,17 +3815,17 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
enqueue_load_avg(cfs_rq, se);
if (se->on_rq) {
update_load_add(&cfs_rq->load, se->load.weight);
- if (!curr) {
- /*
- * The entity's vruntime has been adjusted, so let's check
- * whether the rq-wide min_vruntime needs updated too. Since
- * the calculations above require stable min_vruntime rather
- * than up-to-date one, we do the update at the end of the
- * reweight process.
- */
+ if (!curr)
__enqueue_entity(cfs_rq, se);
- update_min_vruntime(cfs_rq);
- }
+
+ /*
+ * The entity's vruntime has been adjusted, so let's check
+ * whether the rq-wide min_vruntime needs updated too. Since
+ * the calculations above require stable min_vruntime rather
+ * than up-to-date one, we do the update at the end of the
+ * reweight process.
+ */
+ update_min_vruntime(cfs_rq);
}
}