[Crash-utility] kmem -[sS] segfault on 2.6.25.17

[Mike Snitzer]

On Fri, Oct 17, 2008 at 4:39 PM, Mike Snitzer <snitzer at gmail.com> wrote:
> On Fri, Oct 17, 2008 at 4:04 PM, Dave Anderson <anderson at redhat.com> wrote:
>>
>> Mike,
>>
>> Apply this patch to 4.0-7.4 and run it on your live system.
>>
>> It works with the sample vmcore you sent me, and it should also alleviate
>> many of the errors that I suggested might be due to the underlying
>> shifting sands of your live system.
>>
>> I don't know why this is the first report of this, nor why I've never
>> seen this before?  The problem has to do with using invalid entries
>> in the kmem_cache.nodelists[MAXNUMNODES] array of kmem_list3 data
>> structures.  To date, the unused entries have typically been NULL
>> for non-existent memory nodes, but not so with your kernel.
>>
>> Let me know how it works for you.
>
> Hi Dave,
>
> I've tested your patch and crash no longer segfaults.  As for the
> various errors from "shifting sands"; I still see quite a few "free
> list: bad slab pointer:" and "partial list: bad slab pointer:" errors
> for my kmem_caches on both the live and vmcore crash sessions.
>
> Are you saying I shouldn't see many of these errors any more?  Or are
> they still to be expected based on your experience when interacting
> with my vmcore?

OK, I was mistaken... I thought I was using your patched crash but I
was using a stale crash that I had modified to not segfault.

Anyway, in the end when I use your patched crash: Things look very nice!

thanks,
Mike