linux-kernel - Re: [PATCH 2/4] slqb: Record what node is local to a kmem_cache

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]

Message-ID: <84144f020909220638l79329905sf9a35286130e88d0@mail.gmail.com>
Date:	Tue, 22 Sep 2009 16:38:32 +0300
From:	Pekka Enberg <penberg@...helsinki.fi>
To:	Mel Gorman <mel@....ul.ie>
Cc:	Nick Piggin <npiggin@...e.de>,
	Christoph Lameter <cl@...ux-foundation.org>,
	heiko.carstens@...ibm.com, sachinp@...ibm.com,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	Tejun Heo <tj@...nel.org>,
	Benjamin Herrenschmidt <benh@...nel.crashing.org>
Subject: Re: [PATCH 2/4] slqb: Record what node is local to a kmem_cache_cpu

Hi Mel,

On Tue, Sep 22, 2009 at 3:54 PM, Mel Gorman <mel@....ul.ie> wrote:
> When freeing a page, SLQB checks if the page belongs to the local node.
> If it is not, it is considered a remote free. On the allocation side, it
> always checks the local lists and if they are empty, the page allocator
> is called. On memoryless configurations, this is effectively a memory
> leak and the machine quickly kills itself in an OOM storm.
>
> This patch records what node ID is considered local to a CPU. As the
> management structure for the CPU is always allocated from the closest
> node, the node the CPU structure resides on is considered "local".
>
> Signed-off-by: Mel Gorman <mel@....ul.ie>

I don't understand how the memory leak happens from the above
description (or reading the code). page_to_nid() returns some crazy
value at free time? The remote list isn't drained properly?

                        Pekka
--
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/