From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752412Ab0IJKHy (ORCPT ); Fri, 10 Sep 2010 06:07:54 -0400 Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:50152 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751798Ab0IJKHx (ORCPT ); Fri, 10 Sep 2010 06:07:53 -0400 Message-ID: <4C8A0375.4080503@kernel.dk> Date: Fri, 10 Sep 2010 12:07:49 +0200 From: Jens Axboe MIME-Version: 1.0 To: Brian King CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] block: Range check cpu in blk_cpu_to_group References: <201009091741.o89HfPfM011522@d03av02.boulder.ibm.com> In-Reply-To: <201009091741.o89HfPfM011522@d03av02.boulder.ibm.com> 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 On 09/09/2010 07:41 PM, Brian King wrote: > While testing CPU DLPAR, the following problem was discovered. > We were DLPAR removing the first CPU, which in this case was > logical CPUs 0-3. CPUs 0-2 were already marked offline and > we were in the process of offlining CPU 3. After marking > the CPU inactive and offline in cpu_disable, but before the > cpu was completely idle (cpu_die), we ended up in __make_request > on CPU 3. There we looked at the topology map to see which CPU > to complete the I/O on and found no CPUs in the cpu_sibling_map. > This resulted in the block layer setting the completion cpu > to be NR_CPUS, which then caused an oops when we tried to > complete the I/O. > > Fix this by sanity checking the value we return from blk_cpu_to_group > to be a valid cpu value. > > Signed-off-by: Brian King Thanks Brian, applied. -- Jens Axboe