Subject: sched: Limit the number of task migrations per batch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 06 Jun 2011 12:12:51 +0200
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: da77ceac3d20f27310a07a7c346a4ee6b40d6c28
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension
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>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
---
kernel/sched/core.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -56,7 +56,11 @@ const_debug unsigned int sysctl_sched_fe
* 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.