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

From: Christoph Lameter
Date: Mon Jul 21 2008 - 12:20:55 EST


Vegard Nossum wrote:
On Mon, Jul 21, 2008 at 12:50 PM, Ingo Molnar <mingo@xxxxxxx> wrote:
the problem is, most of the crashes dont come with any usable dump. This
is a laptop so netconsole is the only reliable route out - and if
something in networking crashes chances are that it hoses netconsole
before it can get anything out.

Another thing is that i'm activating netconsole on this box via a kernel
boot line and from within a bzImage (to get it activated as early as
possible) - maybe that's a tad too early for certain initialization
sequences?

I could try run tests with netconsole deactivated, if you think that's a
worthwile line of probing this problem. (although that would make me do
blind tests in essence - having kernel log output is really essential.)

How about posting your custom patches for public review? :-D

(There was recently an odd case of kzalloc() succeeding even though it
was called before the slab caches were initialized -- and it only
generated a warning about irqs-on happening too early. I just mean to
say that it _can_ happen. On another machine, it crashed
spectacularly. I guess you're not enabling the netconsole before slab
allocator is up?)


Vegard

Kzalloc for objects > 4k will succeed even during early boot since we will directly call into the page allocator.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/