commit cd1bb94b4a0531e8211a3774f17de831f8285f76
Author: Arun R Bharadwaj <arun@linux.vnet.ibm.com>
Date:   Thu Apr 16 12:15:34 2009 +0530

    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_child_runs_first;
 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,
diff --git a/kernel/sched.c b/kernel/sched.c
index 9c5b4d3..7f1dd56 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -8731,6 +8731,8 @@ void __init sched_init_smp(void)
 }
 #endif /* CONFIG_SMP */
 
+const_debug unsigned int sysctl_timer_migration = 1;
+
 int in_sched_functions(unsigned long addr)
 {
 	return in_lock_functions(addr) ||
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index e3d2c7d..b3ce581 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -324,6 +324,14 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec,
 	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "timer_migration",
+		.data		= &sysctl_timer_migration,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
 #endif
 	{
 		.ctl_name	= CTL_UNNUMBERED,