Re: [Bug #32982] Kernel locks up a few minutes after boot

[Jens Axboe <jaxboe@fusionio.com>]

On 2011-04-17 20:37, Bart Van Assche wrote:
> On Sun, Apr 17, 2011 at 7:03 PM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
>> On Sun, Apr 17, 2011 at 5:57 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
>>> This message has been generated automatically as a part of a summary report
>>> of recent regressions.
>>>
>>> The following bug entry is on the current list of known regressions
>>> from 2.6.38.  Please verify if it still should be listed and let the tracking team
>>> know (either way).
>>>
>>>
>>> Bug-Entry       : http://bugzilla.kernel.org/show_bug.cgi?id=32982
>>> Subject         : Kernel locks up a few minutes after boot
>>> Submitter       : Bart Van Assche <bart.vanassche@gmail.com>
>>> Date            : 2011-04-10 19:55 (8 days old)
>>
>> Is this machine running a RAID5 setup or something like that?
>>
>> There is a known interaction with the new block layer plugging code
>> and MD. The "hung task" report in that bugzilla looks very much like
>> that issue. And you do have "root=/dev/md0", so clearly there's some
>> md thing going on.
>>
>> And bisecting might not work all that well for it, because I suspect
>> it ends up being very much a matter of IO patterns how it triggers.
>>
>> Neil supposedly has a patch for it, but I haven't seen it yet. Neil, Jens?
> 
> (converted top-posting into bottom-posting)
> 
> Hello Linus,
> 
> On the system on which bug #32982 has been triggered md0, md1 and md2
> have been configured as two-disk RAID1 (mirroring).
> 
> I've done my best to trigger enough I/O in order to obtain reliable
> bisect results. A difficulty I encountered during bisecting though was
> that I encountered unbootable kernels (all skipped revisions).

Bart, can you try and pull:

git://git.kernel.dk/linux-2.6-block.git for-linus

into Linus' tree and see if that works? This has, among other things,
Neils fixes for MD.

-- 
Jens Axboe