Re: list corruption in the last few days. (block ? crypto ?)

From: Pekka Enberg
Date: Fri Aug 05 2011 - 05:33:21 EST


On Fri, Aug 5, 2011 at 12:13 PM, Pekka Enberg <penberg@xxxxxxxxxx> wrote:
> On Fri, Aug 5, 2011 at 11:46 AM, Markus Trippelsdorf
> <markus@xxxxxxxxxxxxxxx> wrote:
>> On 2011.08.04 at 21:00 -0400, Dave Jones wrote:
>>> Sometime in the last week, something was merged which causes my laptop
>>> to lock up occasionally.  I can trigger it most of the time just by
>>> doing a kernel build. When it gets to the final linking stage, it locks up hard.
>>>
>>> I finally managed to coax something out of usb console to get the traces below,
>>> which seem to implicate something in the block layer ?
>>>
>>> my root device is an lvm volume on an dmcrypt'd block dev, which might be relevant,
>>> as I don't see this happening on other machines with simpler setups.
>>>
>>> I'm going to try bisecting, but it might take me a few days, because it's
>>> such a pain in the ass to reproduce this reliably.
>>>
>>> [ 5913.233035] ------------[ cut here ]------------
>>> [ 5913.233097] WARNING: at lib/list_debug.c:53 __list_del_entry+0x8d/0x98()
>>> [ 5913.233101] Hardware name: Adamo 13
>>> [ 5913.233105] list_del corruption. prev->next should be ffffea000434fd20, but was ffffea0004199520
>>
>> See also: http://lkml.org/lkml/2011/8/3/37
>
> That's in networking so SLUB lockless patches are almost certainly the
> issue here. Is this with SLUB debugging enabled or not? Christoph, it
> like the partial lists are getting corrupted somehow.

Seeing that mm/vmscan.c shows up in some of the oopses, I wonder if
we're simply forgetting to remove 'struct page' from the partial or
the full list and hand back the page to the page allocator. We're
reusing page->lru in mm/slub.c so we'd end up doing list operations
from both subsystems on the same struct page.

Pekka
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