From 0b9ca2dcabc3c8816a6ee75599cab7bef3330609 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Tue, 8 Jul 2025 18:56:30 +0200 Subject: [PATCH] sched/fair: Always trigger resched at the end of a protected period Always trigger a resched after a protected period even if the entity is still eligible. It can happen that an entity remains eligible at the end of the protected period but must let an entity with a shorter slice to run in order to keep its lag shorter than slice. This is particulalry true with run to parity which tries to maximize the lag. Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20250708165630.1948751-7-vincent.guittot@linaro.org --- kernel/sched/fair.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 1660960d64af..20a845697c1d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1182,14 +1182,6 @@ static inline void update_curr_task(struct task_struct *p, s64 delta_exec) cgroup_account_cputime(p, delta_exec); } -static inline bool resched_next_slice(struct cfs_rq *cfs_rq, struct sched_entity *curr) -{ - if (protect_slice(curr)) - return false; - - return !entity_eligible(cfs_rq, curr); -} - /* * Used by other classes to account runtime. */ @@ -1250,7 +1242,7 @@ static void update_curr(struct cfs_rq *cfs_rq) if (cfs_rq->nr_queued == 1) return; - if (resched || resched_next_slice(cfs_rq, curr)) { + if (resched || !protect_slice(curr)) { resched_curr_lazy(rq); clear_buddies(cfs_rq, curr); } -- 2.47.2