linux-kernel - [PATCH 7/7 v2] sched/fair: Update overutilized detection

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Message-ID: <20241217160720.2397239-8-vincent.guittot@linaro.org>
Date: Tue, 17 Dec 2024 17:07:20 +0100
From: Vincent Guittot <vincent.guittot@...aro.org>
To: mingo@...hat.com,
	peterz@...radead.org,
	juri.lelli@...hat.com,
	dietmar.eggemann@....com,
	rostedt@...dmis.org,
	bsegall@...gle.com,
	mgorman@...e.de,
	vschneid@...hat.com,
	lukasz.luba@....com,
	rafael.j.wysocki@...el.com,
	linux-kernel@...r.kernel.org
Cc: qyousef@...alina.io,
	hongyan.xia2@....com,
	pierre.gondois@....com,
	christian.loehle@....com,
	qperret@...gle.com,
	Vincent Guittot <vincent.guittot@...aro.org>
Subject: [PATCH 7/7 v2] sched/fair: Update overutilized detection

Checking uclamp_min is useless and counterproductive for overutilized state
as misfit can now happen without being in overutilized state

Signed-off-by: Vincent Guittot <vincent.guittot@...aro.org>
---
 kernel/sched/fair.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9bddb094ee21..9eb4c4946ddc 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6870,16 +6870,15 @@ static inline void hrtick_update(struct rq *rq)
 #ifdef CONFIG_SMP
 static inline bool cpu_overutilized(int cpu)
 {
-	unsigned long  rq_util_min, rq_util_max;
+	unsigned long rq_util_max;
 
 	if (!sched_energy_enabled())
 		return false;
 
-	rq_util_min = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MIN);
 	rq_util_max = uclamp_rq_get(cpu_rq(cpu), UCLAMP_MAX);
 
 	/* Return true only if the utilization doesn't fit CPU's capacity */
-	return !util_fits_cpu(cpu_util_cfs(cpu), rq_util_min, rq_util_max, cpu);
+	return !util_fits_cpu(cpu_util_cfs(cpu), 0, rq_util_max, cpu);
 }
 
 /*
-- 
2.43.0