From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262291AbULOHSE (ORCPT ); Wed, 15 Dec 2004 02:18:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262287AbULOHRn (ORCPT ); Wed, 15 Dec 2004 02:17:43 -0500 Received: from cantor.suse.de ([195.135.220.2]:16604 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S262277AbULOHRf (ORCPT ); Wed, 15 Dec 2004 02:17:35 -0500 Date: Wed, 15 Dec 2004 08:17:34 +0100 From: Andi Kleen To: "Martin J. Bligh" Cc: Andi Kleen , 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: <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]> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <686170000.1103094885@[10.10.2.4]> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. > > 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? -Andi