Re: BUG during shutdown - bisected to commit e2912009

[Xiaotian Feng <dfeng@redhat.com>]

On 01/05/2010 02:43 AM, Marc Dionne wrote:
> On Fri, Jan 1, 2010 at 7:42 PM, Peter Zijlstra<peterz@infradead.org>  wrote:
>> On Fri, 2010-01-01 at 19:27 -0500, Marc Dionne wrote:
>>> I'm getting a BUG with current kernels from
>>> kernel/time/clockevents.c:263 when halting the system - a restart
>>> behaves normally.  I don't have a good camera handy at the moment to
>>> capture the call stack on screen, but the call sequence is:
>>>
>>> clockevents_notify
>>> hrtimer_cpu_notify
>>> notifier_call_chain
>>> raw_notifier_call_chain
>>> _cpu_down
>>> disable_nonboot_cpus
>>> kernel_power_off
>>> sys_reboot
>>>
>>> I bisected it down to commit e2912009: sched: Ensure set_task_cpu() is
>>> never called on blocked tasks.  There were a few commits tested along
>>> the way where I got a freeze (with the power still on) instead of a
>>> BUG. Reverting that commit from the current kernel doesn't look
>>> trivial, but the commit immediately preceding this one does halt fine.
>>
>> We somehow seem to trip up the below patch, which doesn't really make
>> sense, as I can't find how task placement would affect the below error.
>>
>> It seems to purely test against the hot-unplugged cpu, not a cpu the
>> task is running on.
>>
>> ---
>> commit bb6eddf7676e1c1f3e637aa93c5224488d99036f
>> Author: Thomas Gleixner<tglx@linutronix.de>
>> Date:   Thu Dec 10 15:35:10 2009 +0100
>
> Probably predictable but worth testing, reverting that patch does
> allow my system to shutdown cleanly.
That BUG_ON was removed by reverting that patch, so you can shutdown 
cleanly.

Could you please attach you kernel config file? I'm a little confused 
about how do you revert e2912009, manually? I can't see any connections 
between e2912009 and bb6eddf7, could you please show me your timer list 
(cat /proc/timer_list)
>
> Marc
>