From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner+w=401wt.eu-S1757625AbZEDQQT@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1757625AbZEDQQT (ORCPT <rfc822;w@1wt.eu>);
	Mon, 4 May 2009 12:16:19 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753466AbZEDQQA
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Mon, 4 May 2009 12:16:00 -0400
Received: from [212.69.161.110] ([212.69.161.110]:56952 "EHLO
	mail09.linbit.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org
	with ESMTP id S1756593AbZEDQP7 (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 4 May 2009 12:15:59 -0400
Date: Mon, 4 May 2009 18:15:03 +0200
From: Lars Ellenberg <lars.ellenberg@linbit.com>
To: Rik van Riel <riel@redhat.com>
Cc: Kyle Moffett <kyle@moffetthome.net>,
       Philipp Reisner <philipp.reisner@linbit.com>,
       linux-kernel@vger.kernel.org, Jens Axboe <jens.axboe@oracle.com>,
       Greg KH <gregkh@suse.de>, Neil Brown <neilb@suse.de>,
       James Bottomley <James.Bottomley@hansenpartnership.com>,
       Sam Ravnborg <sam@ravnborg.org>, Dave Jones <davej@redhat.com>,
       Nikanth Karthikesan <knikanth@suse.de>,
       Lars Marowsky-Bree <lmb@suse.de>,
       "Nicholas A. Bellinger" <nab@linux-iscsi.org>,
       Bart Van Assche <bart.vanassche@gmail.com>
Subject: Re: [PATCH 02/16] DRBD: lru_cache
Message-ID: <20090504161503.GC8728@soda.linbit>
References: <1241090812-13516-1-git-send-email-philipp.reisner@linbit.com> <1241090812-13516-2-git-send-email-philipp.reisner@linbit.com> <1241090812-13516-3-git-send-email-philipp.reisner@linbit.com> <f73f7ab80905021651y54db1e69y87f0487bc06f0522@mail.gmail.com> <20090503062720.GA31340@racke> <f73f7ab80905030706i4afd0902ub42d42d60f01e6a2@mail.gmail.com> <20090503224809.GB6243@racke> <f73f7ab80905031748v2be95af8vcd07c6a77dc348f@mail.gmail.com> <f73f7ab80905031801n1e5ed6b6h84772baabda5f71e@mail.gmail.com> <49FF13D7.8070606@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <49FF13D7.8070606@redhat.com>
User-Agent: Mutt/1.5.18 (2008-05-17)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Mon, May 04, 2009 at 12:12:07PM -0400, Rik van Riel wrote:
> Kyle Moffett wrote:
>> On Sun, May 3, 2009 at 8:48 PM, Kyle Moffett <kyle@moffetthome.net> wrote:
>>> There are a couple trivial tunables you can apply to the model I
>>> provided to dramatically change the effect of memory pressure on the
>>> LRU:
>>>
>>> [...]
>>>
>>
>> Ooh, I forgot to mention another biggie:  There's a way to allocate a
>> reserve pool of memory (I don't remember the exact API, sorry), which
>> can be attached to a specific kmem_cache to be used by processes
>> attempting writeout.  This would allow you to allocate more in-use
>> elements to make forward progress, even if all of your existing
>> elements are already in-use.
>
> Lars,
>
> is using a mempool for allocation, in combination with a
> shrinker callback for freeing older entries an option for
> DRBD?
>
> It looks like that could get rid of a fair amount of custom infrastructure.

I'm going to look into it.


	Lars