From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: mingo@redhat.com, juri.lelli@redhat.com,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, vschneid@redhat.com,
kprateek.nayak@amd.com, linux-kernel@vger.kernel.org,
qyousef@layalina.io
Subject: Re: [PATCH 3/6 v3] sched/eevdf: Update slice protection even when resched is already set
Date: Fri, 26 Jun 2026 09:21:28 +0200 [thread overview]
Message-ID: <20260626072128.GI1181229@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20260624151229.1710703-4-vincent.guittot@linaro.org>
On Wed, Jun 24, 2026 at 05:12:26PM +0200, Vincent Guittot wrote:
> Even if resched is already set, we might want to update or even cancel
> the slice protection and ensure that the newly waking task will be the
> next one to run.
>
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
> ---
> 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 8639086e5d9e..854f3a9f1d80 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -9804,7 +9804,7 @@ static void wakeup_preempt_fair(struct rq *rq, struct task_struct *p, int wake_f
> * prevents us from potentially nominating it as a false LAST_BUDDY
> * below.
> */
> - if (test_tsk_need_resched(rq->curr))
> + if (!sched_feat(PREEMPT_SHORT) && test_tsk_need_resched(rq->curr))
> return;
>
> if (!sched_feat(WAKEUP_PREEMPTION))
This one is leading to boot splats for me -- let me try and figure out
why.
next prev parent reply other threads:[~2026-06-26 7:21 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-24 15:12 [PATCH 0/6 v3] sched/eevdf: Improve scheduling latency of short slice task Vincent Guittot
2026-06-24 15:12 ` [PATCH 1/6 v3] sched/fair: Set next buddy for preempt short Vincent Guittot
2026-06-25 6:24 ` K Prateek Nayak
2026-06-25 12:40 ` Vincent Guittot
2026-06-25 12:43 ` Peter Zijlstra
2026-06-26 6:54 ` Peter Zijlstra
2026-06-26 7:02 ` Vincent Guittot
2026-06-26 8:08 ` Peter Zijlstra
2026-06-26 8:55 ` Vincent Guittot
2026-06-30 9:03 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
2026-06-24 15:12 ` [PATCH 2/6 v3] sched/eevdf: Take into account current's lag when updating slice protection Vincent Guittot
2026-06-30 9:03 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
2026-06-24 15:12 ` [PATCH 3/6 v3] sched/eevdf: Update slice protection even when resched is already set Vincent Guittot
2026-06-26 7:21 ` Peter Zijlstra [this message]
2026-06-26 7:46 ` Peter Zijlstra
2026-06-30 9:03 ` [tip: sched/core] sched/core: Fix inter-class wakeup_preempt() tip-bot2 for Peter Zijlstra
2026-06-30 9:03 ` [tip: sched/core] sched/eevdf: Update slice protection even when resched is already set tip-bot2 for Vincent Guittot
2026-06-24 15:12 ` [PATCH 4/6 v3] sched/eevdf: Cancel slice protection if short slice task is eligible Vincent Guittot
2026-06-25 6:00 ` K Prateek Nayak
2026-06-25 12:40 ` Vincent Guittot
2026-06-26 5:51 ` Shubhang Kaushik
2026-06-26 7:39 ` Vincent Guittot
2026-06-30 9:03 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
2026-06-24 15:12 ` [PATCH 5/6 v3] sched/eevdf: Always update slice protection Vincent Guittot
2026-06-30 9:03 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
2026-06-24 15:12 ` [PATCH 6/6 v3] sched/eevdf: Speedup short slice task scheduling Vincent Guittot
2026-06-25 7:37 ` K Prateek Nayak
2026-06-25 8:37 ` Peter Zijlstra
2026-06-25 10:09 ` Peter Zijlstra
2026-06-25 12:57 ` Vincent Guittot
2026-06-25 12:59 ` Vincent Guittot
2026-06-25 22:28 ` Peter Zijlstra
2026-06-26 3:57 ` K Prateek Nayak
2026-06-26 6:41 ` Peter Zijlstra
2026-06-26 7:05 ` Vincent Guittot
2026-06-26 7:18 ` Peter Zijlstra
2026-06-26 7:54 ` Peter Zijlstra
2026-06-26 8:55 ` Vincent Guittot
2026-06-26 13:55 ` Vincent Guittot
2026-06-29 14:25 ` Vincent Guittot
2026-06-25 14:55 ` Vincent Guittot
2026-06-25 12:51 ` Vincent Guittot
2026-06-25 8:33 ` Peter Zijlstra
2026-06-30 9:03 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
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