ARM: CPU hotplug: ensure correct ordering of unplug
Don't call idle_task_exit() with interrupts disabled, and ensure
that we have a memory barrier after interrupts are disabled but
before signalling that this CPU has shut down.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 8c81ff9..1a1c5e2 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -269,9 +269,11 @@
{
unsigned int cpu = smp_processor_id();
- local_irq_disable();
idle_task_exit();
+ local_irq_disable();
+ mb();
+
/* Tell __cpu_die() that this CPU is now safe to dispose of */
complete(&cpu_died);