From: Manfred Spraul <manfred@colorfullife.com>
To: Hugh Dickins <hugh@veritas.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>,
Linus Torvalds <torvalds@osdl.org>, Andi Kleen <ak@suse.de>,
Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org
Subject: Re: bad page state under possibly oom situation
Date: Thu, 03 Nov 2005 07:38:09 +0100 [thread overview]
Message-ID: <4369B051.7050303@colorfullife.com> (raw)
In-Reply-To: <Pine.LNX.4.61.0511021614110.10299@goblin.wat.veritas.com>
Hugh Dickins wrote:
>(I don't know that it makes any difference, but was this particular report
>from 2.6.9-rc2 or from 2.6.14 or from something else? In both 2.6.9 and
>2.6.14, flags 0x90 mean PG_slab|PG_dirty.)
>
>
>
A very odd combination:
- free_pages_check() ensures that neither PG_slab nor PG_dirty are set
- prep_new_page() complains that both PG_slab and PG_dirty are set
- AFAICS slab doesn't set PG_dirty, and noone except slab set PG_slab.
I don't understand how two wrong bits can end up in page->flags.
Dipankar, could you modify bad_page() and hexdump +-128 bytes? Perhaps
someone overwrites random memory. Or change the value of PG_slab to 20
and check if page->flags remains 0x90.
--
Manfred
next prev parent reply other threads:[~2005-11-03 6:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-11-02 14:35 bad page state under possibly oom situation Dipankar Sarma
2005-11-02 16:33 ` Hugh Dickins
2005-11-02 19:48 ` Dipankar Sarma
2005-11-02 20:33 ` Hugh Dickins
2005-11-02 23:32 ` Nick Piggin
2005-11-03 6:38 ` Manfred Spraul [this message]
2005-11-03 21:11 ` Dipankar Sarma
2005-11-03 21:59 ` Hugh Dickins
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