Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751862AbWB1B4S (ORCPT ); Mon, 27 Feb 2006 20:56:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751877AbWB1B4S (ORCPT ); Mon, 27 Feb 2006 20:56:18 -0500 Received: from omx1-ext.sgi.com ([192.48.179.11]:8107 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S1751862AbWB1B4R (ORCPT ); Mon, 27 Feb 2006 20:56:17 -0500 Date: Mon, 27 Feb 2006 17:56:03 -0800 From: Paul Jackson To: Christoph Lameter Cc: ak@suse.de, dgc@sgi.com, steiner@sgi.com, Simon.Derr@bull.net, linux-kernel@vger.kernel.org, clameter@sgi.com Subject: Re: [PATCH 01/02] cpuset memory spread slab cache filesys Message-Id: <20060227175603.e858eade.pj@sgi.com> In-Reply-To: References: <20060227070209.1994.26823.sendpatchset@jackhammer.engr.sgi.com> <200602272202.34346.ak@suse.de> <200602272339.42574.ak@suse.de> Organization: SGI X-Mailer: Sylpheed version 2.1.7 (GTK+ 2.4.9; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1839 Lines: 43 Hmmm ... your thread with Andi confuses me ... Oh well. I take it that Andi is suggesting that there be the option to override the tasks mempolicy, in the particular case of these file i/o slab caches, with an interleave over the online nodes. This option would be useful in the case that a system is not using cpusets, but still wants to spread out these particular (sometimes large) file i/o caches. Questions for Andi: 1) Are you content to have such a interleave of these particular file i/o slabs triggered by a mm/mempolicy.c option? Or do you think we need some sort of task external API to invoke this policy? If mempolicy API works, then I would think that someone, such as yourself or Christoph, could easily enough propose an extension to the mempolicy API that invoked such a policy. It could leverage some of the apparatus already provided by my current patchset here, such as the per-slab SLAB_MEMP_SPREAD flag settings, the task PF_* flag bits and the hook in ____cache_alloc() to call out to alternate_node_alloc(). If a system wide API (that can be externally imposed on some or all tasks from outside the task) is desirable, then I am left wondering why you don't use cpusets for this. 2) Do you recommend that the page (file buffer) cache also be interleavable, across all online nodes, if optionally requested, on systems not using cpusets? -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.925.600.0401 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/