linux-kernel - [PATCH] sched/topology: remove redundant cpumask_and in init_overlap_sched

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Message-ID: <20210304222944.32504-1-song.bao.hua@hisilicon.com>
Date:   Fri, 5 Mar 2021 11:29:44 +1300
From:   Barry Song <song.bao.hua@...ilicon.com>
To:     <valentin.schneider@....com>, <vincent.guittot@...aro.org>,
        <mingo@...hat.com>, <peterz@...radead.org>,
        <juri.lelli@...hat.com>, <dietmar.eggemann@....com>,
        <rostedt@...dmis.org>, <bsegall@...gle.com>, <mgorman@...e.de>
CC:     <linux-kernel@...r.kernel.org>, <linuxarm@...neuler.org>,
        Barry Song <song.bao.hua@...ilicon.com>
Subject: [PATCH] sched/topology: remove redundant cpumask_and in init_overlap_sched_group

mask is built in build_balance_mask() by for_each_cpu(i, sg_span), so
it must be a subset of sched_group_span(sg). Though cpumask_first_and
doesn't lead to a wrong result of balance cpu, it is pointless to do
cpumask_and again.

Signed-off-by: Barry Song <song.bao.hua@...ilicon.com>
---
 kernel/sched/topology.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 12f8058..45f3db2 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -934,7 +934,7 @@ static void init_overlap_sched_group(struct sched_domain *sd,
 	int cpu;
 
 	build_balance_mask(sd, sg, mask);
-	cpu = cpumask_first_and(sched_group_span(sg), mask);
+	cpu = cpumask_first(mask);
 
 	sg->sgc = *per_cpu_ptr(sdd->sgc, cpu);
 	if (atomic_inc_return(&sg->sgc->ref) == 1)
-- 
1.8.3.1