From e7e24442a1ef3a4d4049bbeb8b3b183e9bc45e77 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Fri, 14 Apr 2017 17:32:07 +0200
Subject: [PATCH] sched/topology: Simplify build_overlap_sched_groups()
References: bnc#978907 Scheduler performance -- topology
Patch-mainline: v4.13-rc1
Git-commit: 91eaed0d61319f58a9f8e43d41a8cbb069b4f73d
Now that the first group will always be the previous domain of this
@cpu this can be simplified.
In fact, writing the code now removed should've been a big clue I was
doing it wrong :/
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
kernel/sched/topology.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 10096278ec1c..6cd482e88abb 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -573,7 +573,7 @@ static void init_overlap_sched_group(struct sched_domain *sd,
static int
build_overlap_sched_groups(struct sched_domain *sd, int cpu)
{
- struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg;
+ struct sched_group *first = NULL, *last = NULL, *sg;
const struct cpumask *span = sched_domain_span(sd);
struct cpumask *covered = sched_domains_tmpmask;
struct sd_data *sdd = sd->private;
@@ -603,15 +603,6 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
init_overlap_sched_group(sd, sg, i);
- /*
- * Make sure the first group of this domain contains the
- * canonical balance CPU. Otherwise the sched_domain iteration
- * breaks. See update_sg_lb_stats().
- */
- if ((!groups && cpumask_test_cpu(cpu, sg_span)) ||
- group_balance_cpu(sg) == cpu)
- groups = sg;
-
if (!first)
first = sg;
if (last)
@@ -619,7 +610,7 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
last = sg;
last->next = first;
}
- sd->groups = groups;
+ sd->groups = first;
return 0;