linux-kernel - [PATCH] sched: Do not zero sg->cpumask and sg->sgp->power in build_sched

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Date:	Wed, 30 Apr 2014 14:39:38 +0100
From:	Dietmar Eggemann <dietmar.eggemann@....com>
To:	Peter Zijlstra <peterz@...radead.org>
Cc:	linux-kernel@...r.kernel.org,
	Dietmar Eggemann <dietmar.eggemann@....com>
Subject: [PATCH] sched: Do not zero sg->cpumask and sg->sgp->power in build_sched_groups

From: Dietmar Eggemann <Dietmar.Eggemann@....com>

There is no need to zero struct sched_group member cpumask and struct
sched_group_power member power since both structures are already allocated
as zeroed memory in __sdt_alloc().

This patch has been tested with
BUG_ON(!cpumask_empty(sched_group_cpus(sg))); and BUG_ON(sg->sgp->power);
in build_sched_groups() on ARM TC2 and INTEL i5 M520 platform including
CPU hotplug scenarios.

Signed-off-by: Dietmar Eggemann <dietmar.eggemann@....com>
---
 kernel/sched/core.c |    2 --
 1 file changed, 2 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9cae286824bb..6bc51aebbf1b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5807,8 +5807,6 @@ build_sched_groups(struct sched_domain *sd, int cpu)
 			continue;
 
 		group = get_group(i, sdd, &sg);
-		cpumask_clear(sched_group_cpus(sg));
-		sg->sgp->power = 0;
 		cpumask_setall(sched_group_mask(sg));
 
 		for_each_cpu(j, span) {
-- 
1.7.9.5


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