Merge tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel...

[firefly-linux-kernel-4.4.55.git] / arch / x86 / xen / smp.c

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 449f86897db3abeff4cd1f44222a2b73f740b01a..315d8fa0c8fb8070b95422ef03b96a8f27c49d1f 100644 (file)
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -409,6 +409,13 @@ static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */
        play_dead_common();
        HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
        cpu_bringup();
+       /*
+        * Balance out the preempt calls - as we are running in cpu_idle
+        * loop which has been called at bootup from cpu_bringup_and_idle.
+        * The cpucpu_bringup_and_idle called cpu_bringup which made a
+        * preempt_disable() So this preempt_enable will balance it out.
+        */
+       preempt_enable();
 }
 
 #else /* !CONFIG_HOTPLUG_CPU */