Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755273AbaKRWDL (ORCPT ); Tue, 18 Nov 2014 17:03:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39063 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753957AbaKRWDJ (ORCPT ); Tue, 18 Nov 2014 17:03:09 -0500 Date: Tue, 18 Nov 2014 17:02:54 -0500 From: Dave Jones To: Don Zickus Cc: Thomas Gleixner , Linus Torvalds , Linux Kernel , the arch/x86 maintainers Subject: Re: frequent lockups in 3.18rc4 Message-ID: <20141118220254.GA2571@redhat.com> Mail-Followup-To: Dave Jones , Don Zickus , Thomas Gleixner , Linus Torvalds , Linux Kernel , the arch/x86 maintainers References: <20141117170359.GA1382@redhat.com> <20141118020959.GA2091@redhat.com> <20141118023930.GA2871@redhat.com> <20141118145234.GA7487@redhat.com> <20141118215540.GD35311@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141118215540.GD35311@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 18, 2014 at 04:55:40PM -0500, Don Zickus wrote: > > So here we mangle CPU3 in and lose the backtrace for cpu0, which might > > be the real interesting one .... > > Can you provide another dump? The hope is we get something not mangled? Working on it.. > The other option we have done in RHEL is panic the system and let kdump > capture the memory. Then we can analyze the vmcore for the stack trace > cpu0 stored in memory to get a rough idea where it might be if the cpu > isn't responding very well. I don't know if it's because of the debug options I typically run with, or that I'm perpetually cursed, but I've never managed to get kdump to do anything useful. (The last time I tried it was actively harmful in that not only did it fail to dump anything, it wedged the machine so it didn't reboot after panic). Unless there's some magic step missing from the documentation at http://fedoraproject.org/wiki/How_to_use_kdump_to_debug_kernel_crashes then I'm not optimistic it'll be useful. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/