Subject: Re: [bug, netconsole, SLUB] BUG skbuff_head_cache: Poison overwritten

From: Ingo Molnar <[email-masked]>
Date: Fri, 18 Jul 2008 11:05:06 +0200

* Vegard Nossum <[email-masked]> wrote:

> But.. it could also be some random corruption coming from elsewhere. 
> Maybe even bad RAM (it's just a single bit anyway). But that's less 
> likely.

ok, i looked at the logs once more and while i thought that it occured 
twice it only occured once:

  Jul 17 20:22:14 europe kernel: BUG skbuff_head_cache: Poison overwritten

... this would explain why my attempts to bisect and reproduce it 
failed. I got too excited about it being seemingly reproducible and 
possibly bisectable (memory corruption bugs rarely are). My overnight 
reboot-the-same-kernel tests didnt show anything either.

It's a known-reliable system with thousands of bootups:

 Jul 17 20:20:54 europe kernel: Linux version 2.6.26-tip (mingo@europe) 
 (gcc version 4.2.2) #3094 SMP Thu Jul 17 20:19:27 CEST 2008

... but a hw fluke is never out of question. (It wasnt a particularly 
hot day but the evening was unusually humid, maybe that made the 
difference.)

So lets close this for now, it's not a reproducible regression that we 
can act upon. I'll update this thread if anything new happens. 
Netconsole is reliable on this system in any case.

	Ingo