Kernel panic when unpluggin AC adaptor

[Brandon Gooch]

On Tue, May 18, 2010 at 10:47 PM, Brandon Gooch
<jamesbrandongooch at gmail.com> wrote:
> On Tue, May 18, 2010 at 9:04 AM, Giovanni Trematerra
> <giovanni.trematerra at gmail.com> wrote:
>> On Sat, May 15, 2010 at 9:12 PM, Brandon Gooch
>> <jamesbrandongooch at gmail.com> wrote:
>>> On Thu, May 13, 2010 at 7:25 PM, Giovanni Trematerra
>>> <giovanni.trematerra at gmail.com> wrote:
>>>> On Thu, May 13, 2010 at 1:09 AM, Brandon Gooch
>>>> <jamesbrandongooch at gmail.com> wrote:
>>>>> On Wed, May 12, 2010 at 9:41 AM, Attilio Rao <attilio at freebsd.org> wrote:
>>>>>> 2010/5/12 David DEMELIER <demelier.david at gmail.com>:
>>>>>>> I remove the patch, and built the kernel (I updated the src this
>>>>>>> morning) and it does not panic now. It's really odd. If it reappears
>>>>>>> soon I will tell you.
>>>>>>
>>>>>> I looked at the code with Giovanni and I have the feeling that the
>>>>>> race with the idle thread may still be fatal.
>>>>>> We need to fix that.
>>>>>>
>>>>>> Attilio
>>>>>>
>>>>>
>>>>> That seems to be the case, as my laptop shows about an 80-85 % chance
>>>>> of experiencing a panic if left idle for long-ish periods of time (2
>>>>> to 4 hours). I usually rebuild world or big ports overnight, and more
>>>>> often than not I wake up to a panicked machine, same situation every
>>>>> time:
>>>>>
>>>>> ...
>>>>> rman_get_bushandle() at rman_get_bushandle+0x1
>>>>> sched_idletd() at sched_idletd+0x123
>>>>> fork_exit() at fork_exit+0x12a
>>>>> fork_trampoline() at fork_trampoline+0xe
>>>>> ...
>>>>>
>>>>> The kernel/userland is rebuilt, the ports are finished compiling --
>>>>> it's in the time AFTER the completion of all tasks that the machine
>>>>> gets bored and tries to kill itself :)
>>>>>
>>>>> I have seen the AC adapter plug/unplug "hang" in the past on this
>>>>> laptop, but I never made the connection between the events, as
>>>>> nowadays my laptop usually stays plugged in :(
>>>>>
>>>>> Attilio, I hope you can track this one down, let me know if I can do
>>>>> anything to help or test...
>>>>>
>>>>
>>>> Attilio and I came up with this patch. It seems ready for stress
>>>> testing and review
>>>> Please test and report back.
>>>>
>>>> Thank you
>>>>
>>>> P.S: all the faults are only mine.
>>>
>>> I tried the patch, and my kernel panics I panic on boot. I have
>>> 8.5MB(!) of JPG images (6 of them) if anyone needs to see them. I'm
>>> looking for a place to post them, but if anyone wants, I can send via
>>> e-mail...
>>
>> Hi Brandon,
>> Could you please, try this new one? The panic at boot stage should be solved,
>> at least I tried on a 8-way machine and all went ok at boot.
>> Please, remove WITNESS_SKIPSPIN from your kernel config file.
>> This patch might be sub-optimal and contains style(9) error but if it
>> works we are
>> on the right way.
>> Let me know if it works for you.
>
> Applied the patch, built, installed, and booted new kernel: no panic!
>
> I will remove WITNESS_SKIPSPIN and build another kernel. Then I'll
> "try" to trigger the panic (by letting my laptop sit idle after a
> buildworld session).
>
> Thanks for giving this some attention, I hope you and/or others are
> able to get to the bottom of this...

Hey everyone, just reporting in:

The laptop has experienced the longest uptime it's seen in a while --
so far, so good!

I'll keep the machine up and running just in case...

-Brandon