linux-kernel - Re: Vanilla-Kernel 3 - page allocation failure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 27 Oct 2011 09:13:00 +0200
From:	Philipp Herz - Profihost AG <p.herz@...fihost.ag>
To:	David Rientjes <rientjes@...gle.com>
CC:	Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org,
	s.priebe@...fihost.ag
Subject: Re: Vanilla-Kernel 3 - page allocation failure

Am 26.10.2011 22:26, schrieb David Rientjes:
> On Mon, 24 Oct 2011, Philipp Herz - Profihost AG wrote:
>
>> we have recompiled the kernel of one machine with CONFIG_SLUB instead of
>> CONFIG_SLAB, but it is showing similar message.
>>
>> Now it's showing failure at "order:5, mode:0x4020".
>>
>> Call trace can be found at:
>> * http://pastebin.com/uGJiwvG1
>>
>> Comparing kernel 2.6.32 (mm/page_alloc.c) there seams to be the same way of
>> dealing with page allocation.
>>
>> Do you have an idea why these (warning) messages do never appear running
>> 2.6.32?
>>
>
> Do you have CONFIG_COMPACTION enabled?  Perhaps this is a difference in
> the deprecation of lumpy reclaim between 2.6.35 and 2.6.38 and
> defragmentation being done by memory compaction instead.
Yes CONFIG_COMPACTION is enabled as a dependency for 
TRANSPARENT_HUGEPAGE which is different to the configs before.

>
> It won't be triggered synchronously in this context since it's a
> GFP_ATOMIC allocation, which is why it emits a page allocation failure in
> the first place, but it will show whether defragmentation is the issue or
> you're just simply low on memory.
Do you mean that "memory compaction" should be turned off again?

How can I see the difference between "deframentation issue" and "low 
memory"? I did not get this point.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/