From 873340373d5664e038a1442a0c1a0d3aba882f90 Mon Sep 17 00:00:00 2001
From: Gregory Haskins <ghaskins@novell.com>
Date: Mon, 29 Dec 2008 09:39:50 -0500
Subject: [PATCH] --- yaml --- r: 135675 b: refs/heads/master c:
 7e96fa5875d4a9be18d74d3ca7b90518d05bc426 h: refs/heads/master i:   135673:
 dbdca65167d633495493bed10de89cf6f1f9c01c   135671:
 ac47e730d3b9c3c933001e60f6fdece4db2d7df9 v: v3

---
 [refs]               |  2 +-
 trunk/kernel/sched.c | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 3690f9484932..49f64c125c44 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 777c2f389e463428fd7e2871051a84d7fe84b172
+refs/heads/master: 7e96fa5875d4a9be18d74d3ca7b90518d05bc426
diff --git a/trunk/kernel/sched.c b/trunk/kernel/sched.c
index 7729f9a45a8b..94d9a6c5ff94 100644
--- a/trunk/kernel/sched.c
+++ b/trunk/kernel/sched.c
@@ -2984,6 +2984,16 @@ balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
 	pulled++;
 	rem_load_move -= p->se.load.weight;
 
+#ifdef CONFIG_PREEMPT
+	/*
+	 * NEWIDLE balancing is a source of latency, so preemptible kernels
+	 * will stop after the first task is pulled to minimize the critical
+	 * section.
+	 */
+	if (idle == CPU_NEWLY_IDLE)
+		goto out;
+#endif
+
 	/*
 	 * We only want to steal up to the prescribed amount of weighted load.
 	 */
@@ -3030,9 +3040,15 @@ static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
 				sd, idle, all_pinned, &this_best_prio);
 		class = class->next;
 
+#ifdef CONFIG_PREEMPT
+		/*
+		 * NEWIDLE balancing is a source of latency, so preemptible
+		 * kernels will stop after the first task is pulled to minimize
+		 * the critical section.
+		 */
 		if (idle == CPU_NEWLY_IDLE && this_rq->nr_running)
 			break;
-
+#endif
 	} while (class && max_load_move > total_load_moved);
 
 	return total_load_moved > 0;