From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753275Ab1K1O1P (ORCPT ); Mon, 28 Nov 2011 09:27:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:13662 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751796Ab1K1O1N (ORCPT ); Mon, 28 Nov 2011 09:27:13 -0500 Date: Mon, 28 Nov 2011 09:26:52 -0500 From: Vivek Goyal To: "K.Prasad" Cc: Dave Anderson , Borislav Petkov , Tony Luck , "Eric W. Biederman" , tachibana@mxm.nes.nec.co.jp, oomichi@mxs.nes.nec.co.jp, Valdis Kletnieks , Nick Bowler , linux-kernel@vger.kernel.org Subject: Re: [RFC Patch 1/2][slimdump] Append CRASH_REASON to VMCOREINFO elf-note Message-ID: <20111128142652.GB20758@redhat.com> References: <20111121101157.GA10194@in.ibm.com> <36c0c64c-9ccb-44a0-a81c-1071604cbdec@zmail15.collab.prod.int.phx2.redhat.com> <20111123173930.GC2515@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111123173930.GC2515@in.ibm.com> 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, Nov 23, 2011 at 11:09:31PM +0530, K.Prasad wrote: > On Mon, Nov 21, 2011 at 10:19:31AM -0500, Dave Anderson wrote: > > > > > > ----- Original Message ----- > > > Allow various crash paths to append the reason of crash into the > > > VMCOREINFO elf-note through the field CRASH_REASON. We also make the > > > fatal machine check exceptions append "PANIC_MCE" as the crash > > > reason. This string will be recognised by upstream tools like makedumpfile and > > > crash to generate slimdump. > > > > I don't understand -- how could "various paths" append a reason? > > The patch below seems to return "PANIC_MCE" for every x86 crash. > > What am I missing? > > > > Dave > > > > Yes, presently it can only be "PANIC_MCE" for MCE crashes in x86 (not > for every crash though). > > With increased usage, we should move this code to a generic location and > let each of these crash paths return a string to be appended. In fact it > doesn't have to be a string for CRASH_REASON but just an encoding of the > various crash types into numbers. User-space tools could then do a lookup > for getting the right crash string. Probably string is a better idea? Where do we do lookup to find out what maps to what? This would require kernel exporting this info in a header and then comes the issue of having same kernel version info. Or the issue of analyzing kernel dumps on the same machine. Storing a string will atleast help that one does not have to worry about mapping error code. makedumpfile shall have to grep for exact same string though. Thanks Vivek