From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758472AbZFZVKz (ORCPT ); Fri, 26 Jun 2009 17:10:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754658AbZFZVKr (ORCPT ); Fri, 26 Jun 2009 17:10:47 -0400 Received: from hera.kernel.org ([140.211.167.34]:59727 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751723AbZFZVKq (ORCPT ); Fri, 26 Jun 2009 17:10:46 -0400 Message-ID: <4A4538FE.2090101@kernel.org> Date: Fri, 26 Jun 2009 14:09:18 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Andrew Morton 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 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> <20090626135428.d8f88a70.akpm@linux-foundation.org> In-Reply-To: <20090626135428.d8f88a70.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > 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 " ==> 32bit assume NORMAL_MEMORY bit and HIGH_MEMORY bit are set for Node0 always. and some code only check if HIGH_MEMORY is there to know if NORMAL_MEMORY is there. YH