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authorPeter Zijlstra <peterz@infradead.org>2017-09-06 12:51:31 +0200
committerIngo Molnar <mingo@kernel.org>2017-09-07 09:29:31 +0200
commita731ebe6f17bff9e7ca12ef227f9da4d5bdf8425 (patch)
treebc8e65cc2ff460199206c3c80ce9f6b0527b364a
parentMerge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kerne... (diff)
downloadlinux-a731ebe6f17bff9e7ca12ef227f9da4d5bdf8425.tar.xz
linux-a731ebe6f17bff9e7ca12ef227f9da4d5bdf8425.zip
sched/fair: Fix wake_affine_llc() balancing rules
Chris Wilson reported that the SMT balance rules got the +1 on the wrong side, resulting in a bias towards the current LLC; which the load-balancer would then try and undo. Reported-by: Chris Wilson <chris@chris-wilson.co.uk> Tested-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.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 Fixes: 90001d67be2f ("sched/fair: Fix wake_affine() for !NUMA_BALANCING") Link: http://lkml.kernel.org/r/20170906105131.gqjmaextmn3u6tj2@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/sched/fair.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8d5868771cb3..9dd2ce1e5ca2 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5435,7 +5435,7 @@ wake_affine_llc(struct sched_domain *sd, struct task_struct *p,
return false;
/* if this cache has capacity, come here */
- if (this_stats.has_capacity && this_stats.nr_running < prev_stats.nr_running+1)
+ if (this_stats.has_capacity && this_stats.nr_running+1 < prev_stats.nr_running)
return true;
/*