Re: [memcg BUG] unable to handle kernel NULL pointer derefence at 00000000

KAMEZAWA Hiroyuki
2008-10-21T06:55:21Z

On Tue, 21 Oct 2008 14:20:27 +0800
Li Zefan <lizf@cn.fujitsu.com> wrote:

> > BTW, "allocate all page_cgroup at boot" patch goes to Linus' git. Wow.
> >
>
> But seems this patch causes kernel panic at system boot ... (or maybe one of other
> memcg patches?)
>
> I wrote down the panic manually:
>
> BUG: unable to handle kernel NULL pointer dereference at 00000000
> IP: page_cgroup_zoneinfo + 0xa
>
> Call Trace:
> ? mem_cgroup_charge_common + 0x17d
> ? mem_cgroup_charge
> ? add_to_page_cache_locked
> ? add_to_page_cache_lru
> ? find_or_create_page
> ? __getblk
> ? ext3_get_inode_loc
> ? ext3_iget
> ? ext3_lookup
>
> Tell me if you need extra information.
>
Hmm, it's curious but page_cgroup->page seems to be NULL...
Could you show disassemble code of page_cgroup_zoneinfo() ?

BTW, this happens always ?

Thanks,
-Kame