Patch "sched/topology: Optimize build_group_mask()" has been added to the 4.12-stable tree

Patch "sched/topology: Optimize build_group_mask()" has been added to the 4.12-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    sched/topology: Optimize build_group_mask()

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     sched-topology-optimize-build_group_mask.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f32d782e31bf079f600dcec126ed117b0577e85c Mon Sep 17 00:00:00 2001
From: Lauro Ramos Venancio <lvenanci@redhat.com>
Date: Thu, 20 Apr 2017 16:51:40 -0300
Subject: sched/topology: Optimize build_group_mask()

From: Lauro Ramos Venancio <lvenanci@redhat.com>

commit f32d782e31bf079f600dcec126ed117b0577e85c upstream.

The group mask is always used in intersection with the group CPUs. So,
when building the group mask, we don't have to care about CPUs that are
not part of the group.

Signed-off-by: Lauro Ramos Venancio <lvenanci@redhat.com>
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: lwang@redhat.com
Cc: riel@redhat.com
Link: http://lkml.kernel.org/r/1492717903-5195-2-git-send-email-lvenanci@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/sched/topology.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -490,12 +490,12 @@ enum s_alloc {
  */
 static void build_group_mask(struct sched_domain *sd, struct sched_group *sg)
 {
-	const struct cpumask *span = sched_domain_span(sd);
+	const struct cpumask *sg_span = sched_group_cpus(sg);
 	struct sd_data *sdd = sd->private;
 	struct sched_domain *sibling;
 	int i;
 
-	for_each_cpu(i, span) {
+	for_each_cpu(i, sg_span) {
 		sibling = *per_cpu_ptr(sdd->sd, i);
 		if (!cpumask_test_cpu(i, sched_domain_span(sibling)))
 			continue;


Patches currently in stable-queue which might be from lvenanci@redhat.com are

queue-4.12/sched-topology-fix-building-of-overlapping-sched-groups.patch
queue-4.12/sched-topology-fix-overlapping-sched_group_mask.patch
queue-4.12/sched-topology-optimize-build_group_mask.patch