timers: /proc/sys sysctl hook to enable timer migration

* Arun R Bharadwaj <arun@linux.vnet.ibm.com> [2009-04-16 12:11:36]:

This patch creates the /proc/sys sysctl interface at
/proc/sys/kernel/timer_migration

Timer migration is enabled by default.

To disable timer migration, when CONFIG_SCHED_DEBUG = y,

echo 0 > /proc/sys/kernel/timer_migration

Signed-off-by: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b4c38bc..6185040 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1766,6 +1766,7 @@
 extern unsigned int sysctl_sched_features;
 extern unsigned int sysctl_sched_migration_cost;
 extern unsigned int sysctl_sched_nr_migrate;
+extern unsigned int sysctl_timer_migration;
 
 int sched_nr_latency_handler(struct ctl_table *table, int write,
 		struct file *file, void __user *buffer, size_t *length,