[PATCH] sched: change prio bias only if queued

prio_bias should only be adjusted in set_user_nice if p is actually currently
queued.
Signed-off-by: Con Kolivas <kernel@kolivas.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/sched.c

@@ -3508,25 +3508,24 @@ void set_user_nice(task_t *p, long nice)
 	 * not SCHED_NORMAL:
 	 */
 	if (rt_task(p)) {
-		dec_prio_bias(rq, p->static_prio);
 		p->static_prio = NICE_TO_PRIO(nice);
-		inc_prio_bias(rq, p->static_prio);
 		goto out_unlock;
 	}
 	array = p->array;
-	if (array)
+	if (array) {
 		dequeue_task(p, array);
+		dec_prio_bias(rq, p->static_prio);
+	}
 
 	old_prio = p->prio;
 	new_prio = NICE_TO_PRIO(nice);
 	delta = new_prio - old_prio;
-	dec_prio_bias(rq, p->static_prio);
 	p->static_prio = NICE_TO_PRIO(nice);
-	inc_prio_bias(rq, p->static_prio);
 	p->prio += delta;
 
 	if (array) {
 		enqueue_task(p, array);
+		inc_prio_bias(rq, p->static_prio);
 		/*
 		 * If the task increased its priority or is running and
 		 * lowered its priority, then reschedule its CPU: