[PATCH] clockevent: don't remove broadcast device when cpu is dead

From: Xiaotian Feng <dfeng@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Xiaotian Feng <dfeng@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Magnus Damm <damm@igel.co.jp>,
	H Hartley Sweeten <hsweeten@visionengravers.com>
Subject: [PATCH] clockevent: don't remove broadcast device when cpu is dead
Date: Thu,  7 Jan 2010 11:22:44 +0800	[thread overview]
Message-ID: <1262834564-13033-1-git-send-email-dfeng@redhat.com> (raw)

Marc reported BUG during shutdown, after debugging, kernel is trying
to remove a broadcast device which mode is CLOCK_EVT_MODE_ONESHOT.

The root cause for this bug is that in clockevents_notify,
"cpumask_weight(dev->cpumask) == 1" is always true even if dev is a
broadcast device. We need to use tick_is_broadcast_device to check
if it is a broadcast device.

Reported-by: Marc Dionne <marc.c.dionne@gmail.com>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Magnus Damm <damm@igel.co.jp>
Cc: H Hartley Sweeten <hsweeten@visionengravers.com>
---
 kernel/time/clockevents.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
index 6f740d9..0223d83 100644
--- a/kernel/time/clockevents.c
+++ b/kernel/time/clockevents.c
@@ -259,7 +259,7 @@ void clockevents_notify(unsigned long reason, void *arg)
 		cpu = *((int *)arg);
 		list_for_each_entry_safe(dev, tmp, &clockevent_devices, list) {
 			if (cpumask_test_cpu(cpu, dev->cpumask) &&
-			    cpumask_weight(dev->cpumask) == 1) {
+			    !tick_is_broadcast_device(dev)) {
 				BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
 				list_del(&dev->list);
 			}
-- 
1.6.5.2

