From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from cl-3117.ham-01.de.sixxs.net ([2001:6f8:900:c2c::2] helo=mail.skyhub.de) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1RBQcs-0000Fc-JQ for kexec@lists.infradead.org; Wed, 05 Oct 2011 12:31:07 +0000 Date: Wed, 5 Oct 2011 14:31:02 +0200 From: Borislav Petkov Subject: Re: [Patch 1/4][kernel][slimdump] Add new elf-note of type NT_NOCOREDUMP to capture slimdump Message-ID: <20111005123102.GA509@gere.osrc.amd.com> References: <20111003070735.GJ2223@in.ibm.com> <20111003073203.GA22694@in.ibm.com> <20111003120336.GK2223@in.ibm.com> <20111004063440.GB5723@liondog.tnic> <20111005070728.GA2235@in.ibm.com> <20111005073111.GA13478@liondog.tnic> <26571.1317815746@turing-police.cc.vt.edu> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <26571.1317815746@turing-police.cc.vt.edu> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Valdis.Kletnieks@vt.edu Cc: oomichi@mxs.nes.nec.co.jp, "Luck, Tony" , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, tachibana@mxm.nes.nec.co.jp, Andi Kleen , anderson@redhat.com, "Eric W. Biederman" , "K.Prasad" , Vivek Goyal , crash-utility@redhat.com On Wed, Oct 05, 2011 at 07:55:46AM -0400, Valdis.Kletnieks@vt.edu wrote: > On Wed, 05 Oct 2011 09:31:11 +0200, Borislav Petkov said: > > On Wed, Oct 05, 2011 at 12:37:28PM +0530, K.Prasad wrote: > > > > True. Like stated by me earlier, there could be two possible outcomes > > > from capturing memory dump in such cases - they're either dangerous or > > > doesn't make sense. > > > > Why, in the second example the only corruption is to the L2 cache so > > your memory image is intact. Why wouldn't you want to capture a memory > > dump then? It is business as usual in that case. > > I'll bite. What's the use case for bothering to capture a memory dump when > you're looking at an MCE that indicates L2 cache corruption? What additional > useful information could you possibly get from the dump? This was just a hypothetical example to show that you need a more finer-grained differentiation between fatal MCEs when deciding to dump or not to dump :-) and not to unconditionally _not_ dump just because we're going to panic. -- Regards/Gruss, Boris. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934615Ab1JEMbI (ORCPT ); Wed, 5 Oct 2011 08:31:08 -0400 Received: from mail.skyhub.de ([78.46.96.112]:59306 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934330Ab1JEMbG (ORCPT ); Wed, 5 Oct 2011 08:31:06 -0400 Date: Wed, 5 Oct 2011 14:31:02 +0200 From: Borislav Petkov To: Valdis.Kletnieks@vt.edu Cc: "K.Prasad" , "Eric W. Biederman" , linux-kernel@vger.kernel.org, crash-utility@redhat.com, kexec@lists.infradead.org, Vivek Goyal , Andi Kleen , "Luck, Tony" , anderson@redhat.com, tachibana@mxm.nes.nec.co.jp, oomichi@mxs.nes.nec.co.jp Subject: Re: [Patch 1/4][kernel][slimdump] Add new elf-note of type NT_NOCOREDUMP to capture slimdump Message-ID: <20111005123102.GA509@gere.osrc.amd.com> References: <20111003070735.GJ2223@in.ibm.com> <20111003073203.GA22694@in.ibm.com> <20111003120336.GK2223@in.ibm.com> <20111004063440.GB5723@liondog.tnic> <20111005070728.GA2235@in.ibm.com> <20111005073111.GA13478@liondog.tnic> <26571.1317815746@turing-police.cc.vt.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <26571.1317815746@turing-police.cc.vt.edu> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 05, 2011 at 07:55:46AM -0400, Valdis.Kletnieks@vt.edu wrote: > On Wed, 05 Oct 2011 09:31:11 +0200, Borislav Petkov said: > > On Wed, Oct 05, 2011 at 12:37:28PM +0530, K.Prasad wrote: > > > > True. Like stated by me earlier, there could be two possible outcomes > > > from capturing memory dump in such cases - they're either dangerous or > > > doesn't make sense. > > > > Why, in the second example the only corruption is to the L2 cache so > > your memory image is intact. Why wouldn't you want to capture a memory > > dump then? It is business as usual in that case. > > I'll bite. What's the use case for bothering to capture a memory dump when > you're looking at an MCE that indicates L2 cache corruption? What additional > useful information could you possibly get from the dump? This was just a hypothetical example to show that you need a more finer-grained differentiation between fatal MCEs when deciding to dump or not to dump :-) and not to unconditionally _not_ dump just because we're going to panic. -- Regards/Gruss, Boris.