Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758900AbYFKFLz (ORCPT ); Wed, 11 Jun 2008 01:11:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751395AbYFKFLr (ORCPT ); Wed, 11 Jun 2008 01:11:47 -0400 Received: from mta23.gyao.ne.jp ([125.63.38.249]:36596 "EHLO mx.gate01.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751332AbYFKFLq (ORCPT ); Wed, 11 Jun 2008 01:11:46 -0400 Date: Wed, 11 Jun 2008 14:09:15 +0900 From: Paul Mundt To: Andrew Morton Cc: Rik van Riel , clameter@sgi.com, linux-kernel@vger.kernel.org, lee.schermerhorn@hp.com, kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, eric.whitney@hp.com, Andi Kleen , Ingo Molnar , Andy Whitcroft Subject: Re: [PATCH -mm 13/25] Noreclaim LRU Infrastructure Message-ID: <20080611050914.GA27488@linux-sh.org> Mail-Followup-To: Paul Mundt , Andrew Morton , Rik van Riel , clameter@sgi.com, linux-kernel@vger.kernel.org, lee.schermerhorn@hp.com, kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, eric.whitney@hp.com, Andi Kleen , Ingo Molnar , Andy Whitcroft References: <20080606180506.081f686a.akpm@linux-foundation.org> <20080608163413.08d46427@bree.surriel.com> <20080608135704.a4b0dbe1.akpm@linux-foundation.org> <20080608173244.0ac4ad9b@bree.surriel.com> <20080608162208.a2683a6c.akpm@linux-foundation.org> <20080608193420.2a9cc030@bree.surriel.com> <20080608165434.67c87e5c.akpm@linux-foundation.org> <20080610153702.4019e042@cuia.bos.redhat.com> <20080610143334.c53d7d8a.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080610143334.c53d7d8a.akpm@linux-foundation.org> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2398 Lines: 51 On Tue, Jun 10, 2008 at 02:33:34PM -0700, Andrew Morton wrote: > On Tue, 10 Jun 2008 15:37:02 -0400 > Rik van Riel wrote: > > > On Tue, 10 Jun 2008 12:17:23 -0700 (PDT) > > Christoph Lameter wrote: > > > > > On Sun, 8 Jun 2008, Andrew Morton wrote: > > > > > > > And it will take longer to get those problems sorted out if 32-bt > > > > machines aren't even compiing the new code in. > > > > > > The problem is going to be less if we dependedn on > > > CONFIG_PAGEFLAGS_EXTENDED instead of 64 bit. This means that only certain > > > 32bit NUMA/sparsemem configs cannot do this due to lack of page flags. > > > > > > I did the pageflags rework in part because of Rik's project. > > > > I think your pageflags work freed up a number of bits on 32 > > bit systems, unless someone compiles a 32 bit system with > > support for 4 memory zones (2 bits ZONE_SHIFT) and 64 NUMA > > nodes (6 bits NODE_SHIFT), in which case we should still > > have 24 bits for flags. > > > > Of course, having 64 NUMA nodes and a ZONE_SHIFT of 2 on > > a 32 bit system is probably total insanity already. I > > suspect very few people compile 32 bit with NUMA at all, > > except if it is an architecture that uses DISCONTIGMEM > > instead of zones, in which case ZONE_SHIFT is 0, which > > will free up space too :) > > Maybe it's time to bite the bullet and kill i386 NUMA support. afaik > it's just NUMAQ and a 2-node NUMAish machine which IBM made (as400?) > > arch/sh uses NUMA for 32-bit, I believe. But I don't know what its > maximum node count is. The default for sh NODES_SHIFT is 3. In terms of memory nodes, systems vary from 2 up to 16 or so. It gets gradually more complex in the SMP cases where we are 3-4 levels deep in various types of memories that we expose as nodes (ie, 4-8 CPUs with a dozen different memories or so at various interconnect levels). As far as testing goes, it's part of the regular build and regression testing for a number of boards, which we verify on a daily basis (although admittedly -mm gets far less testing, even though that's where most of the churn in this area tends to be). -- 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/