From 23756a558b882bfe0c9606d107548352be5d139d Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 6 Jun 2011 12:12:51 +0200
Subject: [PATCH 214/327] sched: Limit the number of task migrations per batch

Put an upper limit on the number of tasks which are migrated per batch
to avoid large latencies.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/sched/core.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 63eb4a4dd2e1..919b5b131b79 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -65,7 +65,11 @@ const_debug unsigned int sysctl_sched_features =
  * Number of tasks to iterate in a single balance run.
  * Limited because this is done with IRQs disabled.
  */
+#ifdef CONFIG_PREEMPT_RT
+const_debug unsigned int sysctl_sched_nr_migrate = 8;
+#else
 const_debug unsigned int sysctl_sched_nr_migrate = 32;
+#endif
 
 /*
  * period over which we measure -rt task CPU usage in us.
-- 
2.49.0

