From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932880Ab2IDXLH (ORCPT ); Tue, 4 Sep 2012 19:11:07 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54753 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932809Ab2IDXLE (ORCPT ); Tue, 4 Sep 2012 19:11:04 -0400 Date: Tue, 4 Sep 2012 16:11:02 -0700 From: Andrew Morton To: Wen Congyang Cc: "linux-kernel@vger.kernel.org" , x86@kernel.org, linux-pm@vger.kernel.org, len.brown@intel.com, pavel@ucw.cz, rjw@sisk.pl, tglx@linutronix.de, Ingo Molnar , "H. Peter Anvin" , rusty@rustcorp.com.au, bhelgaas@google.com, David Rientjes Subject: Re: [PATCH 2/2] numa: don't check if node is NUMA_NO_NODE Message-Id: <20120904161102.143ceb6d.akpm@linux-foundation.org> In-Reply-To: <5044665C.5020909@cn.fujitsu.com> References: <504457C8.10209@cn.fujitsu.com> <5044665C.5020909@cn.fujitsu.com> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-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, 03 Sep 2012 16:12:12 +0800 Wen Congyang wrote: > If we don't debug per_cpu maps, the cpu's node is stored in per_cpu variable > numa_node. If node is NUMA_NO_NODE, it means the caller want to clear the > cpu's node. So we should also call set_cpu_numa_node() in this case. The changelog is missing important information. What is the runtime effect of the patch? In other words, please fully describe the runtime effects of the bug which the patch fixed. Please always provide this information. It will help others decide which kernel version(s) should be patched, and will help the maintainers of other kernel trees (especially vendor trees) to work out whether they should backport the fix into their kernels. > --- a/arch/x86/mm/numa.c > +++ b/arch/x86/mm/numa.c > @@ -97,8 +97,7 @@ void __cpuinit numa_set_node(int cpu, int node) > #endif > per_cpu(x86_cpu_to_node_map, cpu) = node; > > - if (node != NUMA_NO_NODE) > - set_cpu_numa_node(cpu, node); > + set_cpu_numa_node(cpu, node); > } > > void __cpuinit numa_clear_node(int cpu)