Subject: sched: Do not compare cpu masks in scheduler
Date: Tue, 27 Sep 2011 08:40:24 -0400
From: Peter Zijlstra <a.p.zijlstra@chello.nl>

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Clark Williams <williams@redhat.com>
Link: http://lkml.kernel.org/r/20110927124423.128129033@goodmis.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 kernel/sched/core.c |   14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

Index: linux-stable/kernel/sched/core.c
===================================================================
--- linux-stable.orig/kernel/sched/core.c
+++ linux-stable/kernel/sched/core.c
@@ -3398,16 +3398,12 @@ static inline void update_migrate_disabl
 	 */
 	mask = tsk_cpus_allowed(p);
 
-	WARN_ON(!cpumask_test_cpu(smp_processor_id(), mask));
+	if (p->sched_class->set_cpus_allowed)
+		p->sched_class->set_cpus_allowed(p, mask);
+	p->nr_cpus_allowed = cpumask_weight(mask);
 
-	if (!cpumask_equal(&p->cpus_allowed, mask)) {
-		if (p->sched_class->set_cpus_allowed)
-			p->sched_class->set_cpus_allowed(p, mask);
-		p->nr_cpus_allowed = cpumask_weight(mask);
-
-		/* Let migrate_enable know to fix things back up */
-		p->migrate_disable |= MIGRATE_DISABLE_SET_AFFIN;
-	}
+	/* Let migrate_enable know to fix things back up */
+	p->migrate_disable |= MIGRATE_DISABLE_SET_AFFIN;
 }
 
 void migrate_disable(void)