[PATCH] SCHED: change_prio_bias_only_if_queued

[Con Kolivas]

On Sat, 21 May 2005 15:00, Con Kolivas wrote:
> Ok I've respun the smp nice support for the cpu scheduler modifications
> that are in current -mm. Tested on 2.6.12-rc4-mm2 on 4x and seems to work
> fine.

Thanks to Peter Williams for noting I should only change the prio_bias if the 
task is queued in set_user_nice.

Con
---

prio_bias should only be adjusted in set_user_nice if p is actually currently
queued.

Signed-off-by: Con Kolivas <kernel@xxxxxxxxxxx>

Index: linux-2.6.12-rc4-mm2/kernel/sched.c
===================================================================
--- linux-2.6.12-rc4-mm2.orig/kernel/sched.c	2005-05-21 14:25:07.000000000 +1000
+++ linux-2.6.12-rc4-mm2/kernel/sched.c	2005-05-23 19:23:10.000000000 +1000
@@ -3399,25 +3399,24 @@ 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:

Attachment: pgp00000.pgp
Description: PGP signature