From: Ingo Molnar <mingo@elte.hu>

This very simple patch temporarily turns off the array-switching within the
current scheduler.

This yields an unfair scheduler (higher-prio CPU loops can starve lower-prio
CPU loops indefinitely), but it gives us most of the benefits of a single
array and gives us a chance to test the effects in isolation.

It would be nice if people could test: basic interactivity and various
SMP/NUMA workloads such as SDET.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Index: linux-2.6.8-rc3-mm2/kernel/sched.c
===================================================================
--- linux-2.6.8-rc3-mm2.orig/kernel/sched.c	2004-08-09 09:44:57.853589855 +1000
+++ linux-2.6.8-rc3-mm2/kernel/sched.c	2004-08-09 09:48:18.758190366 +1000
@@ -2450,11 +2450,7 @@
 
 		if (!rq->expired_timestamp)
 			rq->expired_timestamp = jiffies;
-		/*
-		 * Disable array switching temporarily to investigate
-		 * the effects (note that this doesnt guarantee fairness):
-		 */
-		if (0 && (!TASK_INTERACTIVE(p) || EXPIRED_STARVING(rq))) {
+		if (!TASK_INTERACTIVE(p) || EXPIRED_STARVING(rq)) {
 			enqueue_task(p, rq->expired);
 			if (p->static_prio < rq->best_expired_prio)
 				rq->best_expired_prio = p->static_prio;