clockevent: Don't remove broadcast device when cpu is dead

Marc reported that the BUG_ON in clockevents_notify() triggers on his
system. This happens because the kernel tries to remove an active
clock event device (used for broadcasting) from the device list.

The handling of devices which can be used as per cpu device and as a
global broadcast device is suboptimal.

The simplest solution for now (and for stable) is to check whether the
device is used as global broadcast device, but this needs to be
revisited.

[ tglx: restored the cpuweight check and massaged the changelog ]

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>
LKML-Reference: <1262834564-13033-1-git-send-email-dfeng@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
This commit is contained in:
Xiaotian Feng 2010-01-07 11:22:44 +08:00 committed by Thomas Gleixner
parent 7dc9c484a7
commit ea9d8e3f45

View file

@ -259,7 +259,8 @@ 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) {
cpumask_weight(dev->cpumask) == 1 &&
!tick_is_broadcast_device(dev)) {
BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
list_del(&dev->list);
}