Re: BUG: Bad page map in process udevd (anon_vma: (null)) in2.6.38-rc4

From: Michal Hocko
Date: Thu Feb 17 2011 - 04:09:21 EST


On Wed 16-02-11 12:09:35, Linus Torvalds wrote:
> On Wed, Feb 16, 2011 at 11:50 AM, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > Yup, goodie. It does look like it might be exactly the same thing,
> > except now the offset seems to be 0x1e68 instead of 0x1768.
>
> It was 0x1748 in Eric's case. Background for Michal:
>
> http://lkml.org/lkml/2011/2/14/223

I have seen that thread but I didn't think it is related. I thought
this is an another anon_vma issue. But you seem to be right that the
offset pattern can be related.

>
> Michal - if you can re-create this, it would be wonderful if you can
> enable CONFIG_DEBUG_PAGEALLOC. I didn't find any obvious candidates
> yet.

OK. I have just booted with the same kernel and the config turned on.
Let's see if I am able to reproduce.

Btw.
$ objdump -d ./vmlinux-2.6.38-rc4-00001-g07409af-vmscan-test | grep 0x1e68

didn't print out anything. Do you have any other way to find out the
structure?
--
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9
Czech Republic
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