From f36d340122ae8744e64af0a92a6f77b97542c0a4 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Tue, 30 Nov 2010 12:21:30 +0000
Subject: [PATCH] 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>
---
arch/arm/kernel/smp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 8c81ff9b3732..1a1c5e2b3ef9 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -269,9 +269,11 @@ void __ref cpu_die(void)
{
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);
--
2.34.1