From 74eec63661d46a7153d04c2e0249eeb76cc76d44 Mon Sep 17 00:00:00 2001 From: Vincent Guittot Date: Tue, 8 Jul 2025 18:56:26 +0200 Subject: sched/fair: Fix NO_RUN_TO_PARITY case EEVDF expects the scheduler to allocate a time quantum to the selected entity and then pick a new entity for next quantum. Although this notion of time quantum is not strictly doable in our case, we can ensure a minimum runtime for each task most of the time and pick a new entity after a minimum time has elapsed. Reuse the slice protection of run to parity to ensure such runtime quantum. Signed-off-by: Vincent Guittot Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20250708165630.1948751-3-vincent.guittot@linaro.org --- include/linux/sched.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index 4802fcf738cd..55921385927d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -583,7 +583,15 @@ struct sched_entity { u64 sum_exec_runtime; u64 prev_sum_exec_runtime; u64 vruntime; - s64 vlag; + union { + /* + * When !@on_rq this field is vlag. + * When cfs_rq->curr == se (which implies @on_rq) + * this field is vprot. See protect_slice(). + */ + s64 vlag; + u64 vprot; + }; u64 slice; u64 nr_migrations; -- cgit v1.2.3