Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757459AbYFJThb (ORCPT ); Tue, 10 Jun 2008 15:37:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753856AbYFJThT (ORCPT ); Tue, 10 Jun 2008 15:37:19 -0400 Received: from mx1.redhat.com ([66.187.233.31]:60213 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753496AbYFJThS (ORCPT ); Tue, 10 Jun 2008 15:37:18 -0400 Date: Tue, 10 Jun 2008 15:37:02 -0400 From: Rik van Riel To: Christoph Lameter Cc: Andrew Morton , linux-kernel@vger.kernel.org, lee.schermerhorn@hp.com, kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org, eric.whitney@hp.com Subject: Re: [PATCH -mm 13/25] Noreclaim LRU Infrastructure Message-ID: <20080610153702.4019e042@cuia.bos.redhat.com> In-Reply-To: References: <20080606202838.390050172@redhat.com> <20080606202859.291472052@redhat.com> <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> Organization: Red Hat, Inc X-Mailer: Claws Mail 3.3.1 (GTK+ 2.12.5; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1361 Lines: 34 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 :) -- All Rights Reversed -- 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/