From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933152Ab1EZTL7 (ORCPT ); Thu, 26 May 2011 15:11:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43462 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758281Ab1EZTL6 (ORCPT ); Thu, 26 May 2011 15:11:58 -0400 Date: Thu, 26 May 2011 15:10:08 -0400 From: Vivek Goyal To: Andi Kleen Cc: "K.Prasad" , Linux Kernel Mailing List , "Luck, Tony" , kexec@lists.infradead.org, "Eric W. Biederman" , anderson@redhat.com Subject: Re: [RFC Patch 5/6] slimdump: Capture slimdump for fatal MCE generated crashes Message-ID: <20110526191008.GF29496@redhat.com> References: <20110526170722.GB23266@in.ibm.com> <20110526172305.GA18295@in.ibm.com> <20110526174447.GC29496@redhat.com> <20110526180931.GF4065@one.firstfloor.org> <20110526182618.GD29496@redhat.com> <20110526185838.GG4065@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110526185838.GG4065@one.firstfloor.org> 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 Thu, May 26, 2011 at 08:58:38PM +0200, Andi Kleen wrote: > > If we are just extracting and saving MCE registers from vmcore, then > > reboot time does not increase. It increases only if user decides to > > extract and save extra data from vmcore. > > Hmm I was thinking of user space usually saving the dump first > before analyzing it. But yes it could probably do some minimal > analysis first. In RHEL, now we filter out the dump by default until and unless user decides to no filter the dump with the help of config options. So I think in this case we can just introduce an extra filtering option in "makedumpfile" and ask it to save only MCE registers if it notices that there is NT_MCE type of ELF note in vmcore. I can very well imaging that extracting dmesg along with MCE registers can be useful. If nothing else, it can give us useful information about the system configuration. Zeroing out all the other ELF headers in vmcore takes away the capability to extract log buffers in case of MCE and I think it probably is not the best idea. Thanks Vivek From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QPfyC-00064h-Vs for kexec@lists.infradead.org; Thu, 26 May 2011 19:11:57 +0000 Date: Thu, 26 May 2011 15:10:08 -0400 From: Vivek Goyal Subject: Re: [RFC Patch 5/6] slimdump: Capture slimdump for fatal MCE generated crashes Message-ID: <20110526191008.GF29496@redhat.com> References: <20110526170722.GB23266@in.ibm.com> <20110526172305.GA18295@in.ibm.com> <20110526174447.GC29496@redhat.com> <20110526180931.GF4065@one.firstfloor.org> <20110526182618.GD29496@redhat.com> <20110526185838.GG4065@one.firstfloor.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20110526185838.GG4065@one.firstfloor.org> 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: Andi Kleen Cc: "Luck, Tony" , kexec@lists.infradead.org, Linux Kernel Mailing List , anderson@redhat.com, "Eric W. Biederman" , "K.Prasad" On Thu, May 26, 2011 at 08:58:38PM +0200, Andi Kleen wrote: > > If we are just extracting and saving MCE registers from vmcore, then > > reboot time does not increase. It increases only if user decides to > > extract and save extra data from vmcore. > > Hmm I was thinking of user space usually saving the dump first > before analyzing it. But yes it could probably do some minimal > analysis first. In RHEL, now we filter out the dump by default until and unless user decides to no filter the dump with the help of config options. So I think in this case we can just introduce an extra filtering option in "makedumpfile" and ask it to save only MCE registers if it notices that there is NT_MCE type of ELF note in vmcore. I can very well imaging that extracting dmesg along with MCE registers can be useful. If nothing else, it can give us useful information about the system configuration. Zeroing out all the other ELF headers in vmcore takes away the capability to extract log buffers in case of MCE and I think it probably is not the best idea. Thanks Vivek _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec