Re: BUG during shutdown - bisected to commit e2912009

[Xiaotian Feng <dfeng@redhat.com>]

On 01/06/2010 06:58 AM, Marc Dionne wrote:
> On Tue, Jan 5, 2010 at 5:18 AM, Xiaotian Feng<dfeng@redhat.com>  wrote:
>> This is outputed by sound module, but it will not affect clockevents, could
>> you please try following patch and let me know the output before BUG_ON
>> happens? We can gather more information on the BUG_ON. Thank you.
>>
>> diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
>> index 6f740d9..7c945e8 100644
>> --- a/kernel/time/clockevents.c
>> +++ b/kernel/time/clockevents.c
>> @@ -260,6 +260,9 @@ void clockevents_notify(unsigned long reason, void *arg)
>>                 list_for_each_entry_safe(dev, tmp,&clockevent_devices, list)
>> {
>>                         if (cpumask_test_cpu(cpu, dev->cpumask)&&
>>                             cpumask_weight(dev->cpumask) == 1) {
>> +                               if (dev->mode != CLOCK_EVT_MODE_UNUSED)
>> +                                       printk("invalid dev %s mode %d on
>> cpu %d\n", dev->name,
>> +                                               dev->mode, cpu);
>>                                 BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
>>                                 list_del(&dev->list);
>
> I don't get anything on screen from the printk - is there a trick
> needed to getting printk output at that stage of shutting down?  I
> tried inserting an mdelay() before the BUG, which delayed the bug
> output but still didn't print the invalid dev message.

Did you notice this BUG when you're doing suspend/resume?

Does the BUG still appear if we changed BUG_ON line to BUG_ON(dev->mode 
!= CLOCK_EVT_MODE_UNUSED && dev->mode != CLOCK_EVT_MODE_SHUTDOWN)?

>
> Thanks,
> Marc
>