From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262369AbULOPJL (ORCPT ); Wed, 15 Dec 2004 10:09:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262367AbULOPJK (ORCPT ); Wed, 15 Dec 2004 10:09:10 -0500 Received: from jade.aracnet.com ([216.99.193.136]:53737 "EHLO jade.spiritone.com") by vger.kernel.org with ESMTP id S262364AbULOPI7 (ORCPT ); Wed, 15 Dec 2004 10:08:59 -0500 Date: Wed, 15 Dec 2004 07:08:46 -0800 From: "Martin J. Bligh" To: Andi Kleen cc: Brent Casavant , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-ia64@vger.kernel.org Subject: Re: [PATCH 0/3] NUMA boot hash allocation interleaving Message-ID: <690790000.1103123325@[10.10.2.4]> In-Reply-To: <20041215071734.GO27225@wotan.suse.de> References: <9250000.1103050790@flay> <20041214191348.GA27225@wotan.suse.de> <19030000.1103054924@flay> <20041215040854.GC27225@wotan.suse.de> <686170000.1103094885@[10.10.2.4]> <20041215071734.GO27225@wotan.suse.de> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --Andi Kleen wrote (on Wednesday, December 15, 2004 08:17:34 +0100): > On Tue, Dec 14, 2004 at 11:14:46PM -0800, Martin J. Bligh wrote: >> Well hold on a sec. We don't need to use the hugepages pool for this, >> do we? This is the same as using huge page mappings for the whole of >> kernel space on ia32. As long as it's a kernel mapping, and 16MB aligned >> and contig, we get it for free, surely? > > The whole point of the patch is to not use the direct mapping, but > use a different interleaved mapping on NUMA machines to spread > the memory out over multiple nodes. Right, I know it's not there pre-existant - I was thinking of frigging it by hand though, rather than using the hugepage pool infrastructure. >> > Using other page sizes would be probably tricky because the >> > linux VM can currently barely deal with two page sizes. >> > I suspect handling more would need some VM infrastructure effort >> > at least in the changed port. >> >> For the general case I'd agree. But this is a setup-time only tweak >> of the static kernel mapping, isn't it? > > It's probably not impossible, just lots of ugly special cases. > e.g. how about supporting it for /proc/kcore etc? Hmmm. Yes, not considered those. M.