linux-kernel - [PATCH 5/5] sched/fair: narrow the sched_use_asym

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Date: Wed, 17 Jan 2024 16:57:15 +0800
From: alexs@...nel.org
To: Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Juri Lelli <juri.lelli@...hat.com>,
	Vincent Guittot <vincent.guittot@...aro.org>,
	Dietmar Eggemann <dietmar.eggemann@....com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ben Segall <bsegall@...gle.com>,
	Mel Gorman <mgorman@...e.de>,
	Daniel Bristot de Oliveira <bristot@...hat.com>,
	Valentin Schneider <vschneid@...hat.com>,
	linux-kernel@...r.kernel.org
Cc: Alex Shi <alexs@...nel.org>
Subject: [PATCH 5/5] sched/fair: narrow the sched_use_asym_prio checking scenario

From: Alex Shi <alexs@...nel.org>

Current function doesn't match it's comments, in fact, core_idle
checking is only meaningful with non-SMT.
So make the function right.

Signed-off-by: Alex Shi <alexs@...nel.org>
To: Valentin Schneider <vschneid@...hat.com>
To: Vincent Guittot <vincent.guittot@...aro.org>
To: Peter Zijlstra <peterz@...radead.org>
To: Ingo Molnar <mingo@...hat.com>
---
 kernel/sched/fair.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 96163ab69ae0..0a321f639c79 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -9741,8 +9741,8 @@ group_type group_classify(unsigned int imbalance_pct,
  */
 static bool sched_use_asym_prio(struct sched_domain *sd, int cpu)
 {
-	return (!sched_smt_active()) ||
-		(sd->flags & SD_SHARE_CPUCAPACITY) || is_core_idle(cpu);
+	return	(sd->flags & SD_SHARE_CPUCAPACITY) ||
+		(!sched_smt_active() && is_core_idle(cpu));
 }
 
 static inline bool _sched_asym(struct sched_domain *sd,
-- 
2.43.0