From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755168AbYFJMul (ORCPT ); Tue, 10 Jun 2008 08:50:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753140AbYFJMub (ORCPT ); Tue, 10 Jun 2008 08:50:31 -0400 Received: from mx1.redhat.com ([66.187.233.31]:44551 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753046AbYFJMua (ORCPT ); Tue, 10 Jun 2008 08:50:30 -0400 Date: Tue, 10 Jun 2008 08:50:11 -0400 From: Rik van Riel To: Nick Piggin 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 17/25] Mlocked Pages are non-reclaimable Message-ID: <20080610085011.15bd481e@bree.surriel.com> In-Reply-To: <20080610033130.GK19404@wotan.suse.de> References: <20080606202838.390050172@redhat.com> <20080606202859.522708682@redhat.com> <20080606180746.6c2b5288.akpm@linux-foundation.org> <20080610033130.GK19404@wotan.suse.de> Organization: Red Hat, Inc. X-Mailer: Claws Mail 3.0.2 (GTK+ 2.10.4; x86_64-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 On Tue, 10 Jun 2008 05:31:30 +0200 Nick Piggin wrote: > It should definitely be enabled for 32-bit machines, and enabled by default. > The argument is that 32 bit machines won't have much memory so it won't > be a problem, but a) it also has to work well on other machines without > much memory, and b) it is a nightmare to have significant behaviour changes > like this. For kernel development as well as kernel running. > > If we eventually run out of page flags on 32 bit, then sure this might be > one we could look at geting rid of. Once the code has proven itself. Alternatively, we tell the 32 bit people not to compile their kernel with support for 64 NUMA nodes :) The number of page flags on 32 bits is (32 - ZONE_SHIFT - NODE_SHIFT) after Christoph's cleanup and no longer a fixed number. Does anyone compile a 32 bit kernel with a large (ZONE_SHIFT + NODE_SHIFT)? -- All rights reversed.