From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752910AbZFZU5J (ORCPT ); Fri, 26 Jun 2009 16:57:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751678AbZFZU44 (ORCPT ); Fri, 26 Jun 2009 16:56:56 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:51766 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750803AbZFZU4z (ORCPT ); Fri, 26 Jun 2009 16:56:55 -0400 Date: Fri, 26 Jun 2009 13:54:28 -0700 From: Andrew Morton To: Yinghai Lu Cc: cl@linux-foundation.org, mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, ntl@pobox.com, mel@csn.ul.ie, suresh.b.siddha@intel.com, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, rusty@rustcorp.com.au, steiner@sgi.com, rientjes@google.com, containers@lists.linux-foundation.org Subject: Re: [PATCH] x86: only clear node_states for 64bit Message-Id: <20090626135428.d8f88a70.akpm@linux-foundation.org> In-Reply-To: <4A3FA58A.3010909@kernel.org> References: <4A05269D.8000701@kernel.org> <20090512111623.GG25923@csn.ul.ie> <4A0A64FB.4080504@kernel.org> <20090513145950.GB28097@csn.ul.ie> <4A0C4910.7090508@kernel.org> <4A0C4A2A.6080009@kernel.org> <20090514095414.ba8356e5.akpm@linux-foundation.org> <4A0C4F67.5080802@kernel.org> <20090514102554.b3a36f19.akpm@linux-foundation.org> <4A0C563A.3020100@kernel.org> <4A2758CB.9090404@kernel.org> <4A27FAD4.2010104@kernel.org> <4A2803D1.4070001@kernel.org> <4A3B49BA.40100@kernel.org> <4A3D7419.8040305@kernel.org> <4A3FA58A.3010909@kernel.org> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-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 Mon, 22 Jun 2009 08:38:50 -0700 Yinghai Lu wrote: > Nathan reported that > | commit 73d60b7f747176dbdff826c4127d22e1fd3f9f74 > | Author: Yinghai Lu > | Date: Tue Jun 16 15:33:00 2009 -0700 > | > | page-allocator: clear N_HIGH_MEMORY map before we set it again > | > | SRAT tables may contains nodes of very small size. The arch code may > | decide to not activate such a node. However, currently the early boot > | code sets N_HIGH_MEMORY for such nodes. These nodes therefore seem to be > | active although these nodes have no present pages. > | > | For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too > > the cpuset.mems cgroup attribute on an i386 kvm guest > > fix it by only clearing node_states[N_NORMAL_MEMORY] for 64bit only. > and need to do save/restore for that in find_zone_movable_pfn > There appear to be some words omitted from this changelog - it doesn't make sense. I think that perhaps a line got deleted before "the cpuset.mems cgroup ...". That was the line which actualy describes the bug which we're fixing. Or perhaps it was a single word? "zeroes". I did this: Nathan reported that : : | commit 73d60b7f747176dbdff826c4127d22e1fd3f9f74 : | Author: Yinghai Lu : | Date: Tue Jun 16 15:33:00 2009 -0700 : | : | page-allocator: clear N_HIGH_MEMORY map before we set it again : | : | SRAT tables may contains nodes of very small size. The arch code may : | decide to not activate such a node. However, currently the early boot : | code sets N_HIGH_MEMORY for such nodes. These nodes therefore seem to be : | active although these nodes have no present pages. : | : | For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too : : unintentionally and incorrectly clears the cpuset.mems cgroup attribute on : an i386 kvm guest : : Fix this by only clearing node_states[N_NORMAL_MEMORY] for 64bit only. : and need to do save/restore for that in find_zone_movable_pfn Please check whether that is correct. If not, how should it be changed?