From 7cd2ef17de5e11612001e98b6319f1793239b243 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Wed, 24 Jun 2026 17:12:28 +0200 Subject: [PATCH] sched/eevdf: Always update slice protection Even if p will not preempt current, it modifies the avg_vruntime and possibly the min slice. Make sure to update the slice protection with the updated figures. As an example, Batch and Sched Idle tasks can otherwise get a larger lag than their slice and finaly delay the scheduling of a normal task, which deadline will be a later. Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Tested-by: K Prateek Nayak Link: https://patch.msgid.link/20260624151229.1710703-6-vincent.guittot@linaro.org --- kernel/sched/fair.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9046b2ea68c6..2547a97921ac 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -9867,16 +9867,17 @@ static void wakeup_preempt_fair(struct rq *rq, struct task_struct *p, int wake_f if (cse_is_idle && !pse_is_idle) goto preempt; + update_curr_fair(rq); + if (cse_is_idle != pse_is_idle) - return; + goto update; /* * BATCH and IDLE tasks do not preempt others. */ if (unlikely(!normal_policy(p->policy))) - return; + goto update; - update_curr_fair(rq); /* * If @p has a shorter slice than current and @p is eligible, override * current's slice protection in order to allow preemption. @@ -9893,7 +9894,7 @@ static void wakeup_preempt_fair(struct rq *rq, struct task_struct *p, int wake_f * EEVDF to forcibly queue an ineligible task. */ if ((wake_flags & WF_FORK) || pse->sched_delayed) - return; + goto update; /* Prefer picking wakee soon if appropriate. */ if (sched_feat(NEXT_BUDDY) && set_preempt_buddy(cfs_rq, pse)) { @@ -9934,7 +9935,7 @@ static void wakeup_preempt_fair(struct rq *rq, struct task_struct *p, int wake_f */ if (preempt_action == PREEMPT_WAKEUP_SHORT && entity_eligible(cfs_rq, pse)) goto preempt; - +update: if (sched_feat(RUN_TO_PARITY)) update_protect_slice(cfs_rq, se);