hotplug-use-migrate-disable.patch

Subject: hotplug-use-migrate-disable.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Sun, 17 Jul 2011 19:35:29 +0200

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/cpu.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Index: linux-stable/kernel/cpu.c
===================================================================
--- linux-stable.orig/kernel/cpu.c
+++ linux-stable/kernel/cpu.c
@@ -375,14 +375,13 @@ static int __ref _cpu_down(unsigned int 
 	cpumask_andnot(cpumask, cpu_online_mask, cpumask_of(cpu));
 	set_cpus_allowed_ptr(current, cpumask);
 	free_cpumask_var(cpumask);
-	preempt_disable();
+	migrate_disable();
 	mycpu = smp_processor_id();
 	if (mycpu == cpu) {
 		printk(KERN_ERR "Yuck! Still on unplug CPU\n!");
-		preempt_enable();
+		migrate_enable();
 		return -EBUSY;
 	}
-	preempt_enable();
 
 	err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
 	if (err) {
@@ -432,6 +431,7 @@ static int __ref _cpu_down(unsigned int 
 out_release:
 	cpu_unplug_done(cpu);
 out_cancel:
+	migrate_enable();
 	cpu_hotplug_done();
 	if (!err)
 		cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);