From 17b3279b48835eb522d842eae16f541da3729c8a Mon Sep 17 00:00:00 2001
From: Gregory Haskins <ghaskins@novell.com>
Date: Fri, 25 Jan 2008 21:08:13 +0100
Subject: [PATCH] sched: break out early if RT task cannot be migrated
We don't need to bother searching if the task cannot be migrated
Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
kernel/sched_rt.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 9becc3710b60..72c81322fb9a 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -176,7 +176,8 @@ static int select_task_rq_rt(struct task_struct *p, int sync)
* that is just being woken and probably will have
* cold cache anyway.
*/
- if (unlikely(rt_task(rq->curr))) {
+ if (unlikely(rt_task(rq->curr)) &&
+ (p->nr_cpus_allowed > 1)) {
int cpu = find_lowest_rq(p);
return (cpu == -1) ? task_cpu(p) : cpu;