Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754825AbaKOAgr (ORCPT ); Fri, 14 Nov 2014 19:36:47 -0500 Received: from www.linutronix.de ([62.245.132.108]:55695 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750800AbaKOAgq (ORCPT ); Fri, 14 Nov 2014 19:36:46 -0500 Date: Sat, 15 Nov 2014 01:36:41 +0100 (CET) From: Thomas Gleixner To: Dave Jones cc: Linus Torvalds , Linux Kernel , the arch/x86 maintainers Subject: Re: frequent lockups in 3.18rc4 In-Reply-To: <20141114233213.GA14135@redhat.com> Message-ID: References: <20141114213124.GB3344@redhat.com> <20141114233213.GA14135@redhat.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 14 Nov 2014, Dave Jones wrote: > On Fri, Nov 14, 2014 at 11:55:30PM +0100, Thomas Gleixner wrote: > > > So this looks more like a smp function call fuckup. > > > > I assume Dave is running that stuff on KVM. So it might be worth while > > to look at the IPI magic there. > > no, bare metal. Ok, but that does not change the fact that we are stuck in smp_function_call land. Enabling softlockup_all_cpu_backtrace will probably not help much as we will end up waiting for csd_lock again :( Is the machine still accesible when this happens? If yes, we might enable a few trace points and functions and read out the trace buffer. If not, we could just panic the machine and dump the trace buffer over serial. Sigh tglx -- 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/