sched: symmetric sync vs avg_overlap

Reinstate the weakening of the sync hint if set. This yields a more
symmetric usage of avg_overlap.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/sched.c

@@ -2266,9 +2266,15 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
 	if (!sched_feat(SYNC_WAKEUPS))
 		sync = 0;
 
-	if (!sync && (current->se.avg_overlap < sysctl_sched_migration_cost &&
-			    p->se.avg_overlap < sysctl_sched_migration_cost))
-		sync = 1;
+	if (!sync) {
+		if (current->se.avg_overlap < sysctl_sched_migration_cost &&
+			  p->se.avg_overlap < sysctl_sched_migration_cost)
+			sync = 1;
+	} else {
+		if (current->se.avg_overlap >= sysctl_sched_migration_cost ||
+			  p->se.avg_overlap >= sysctl_sched_migration_cost)
+			sync = 0;
+	}
 
 #ifdef CONFIG_SMP
 	if (sched_feat(LB_WAKEUP_UPDATE)) {