Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752512AbaLCUKC (ORCPT ); Wed, 3 Dec 2014 15:10:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50747 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751482AbaLCUKA (ORCPT ); Wed, 3 Dec 2014 15:10:00 -0500 Date: Wed, 3 Dec 2014 15:09:06 -0500 From: Dave Jones To: Linus Torvalds Cc: Chris Mason , Mike Galbraith , Ingo Molnar , Peter Zijlstra , =?iso-8859-1?Q?D=E2niel?= Fraga , Sasha Levin , "Paul E. McKenney" , Linux Kernel Mailing List , Thomas Gleixner , John Stultz Subject: Re: frequent lockups in 3.18rc4 Message-ID: <20141203200906.GA3118@redhat.com> Mail-Followup-To: Dave Jones , Linus Torvalds , Chris Mason , Mike Galbraith , Ingo Molnar , Peter Zijlstra , =?iso-8859-1?Q?D=E2niel?= Fraga , Sasha Levin , "Paul E. McKenney" , Linux Kernel Mailing List , Thomas Gleixner , John Stultz References: <20141201230339.GA20487@ret.masoncoding.com> <1417529606.3924.26.camel@maggy.simpson.net> <1417540493.21136.3@mail.thefacebook.com> <20141203184111.GA32005@redhat.com> <20141203190045.GB32005@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Wed, Dec 03, 2014 at 11:48:55AM -0800, Linus Torvalds wrote: > On Wed, Dec 3, 2014 at 11:25 AM, Linus Torvalds > wrote: > > > > I don't know. This piece of code: > > > > delta = clocksource_delta(wdnow, cs->wd_last, watchdog->mask); > > > > makes no sense to me. > > Yeah, no, I see what's up. I missed that whole wd_last vs cs_last > pairing. I guess that part is all good. There are other crazy issues > in there, though, like the double test of 'watchdog_reset_pending'. So > I still wonder, though, since that odd 96-second delta is just insane > and makes no sense from a TSC standpoint (it's closer to a 32-bit > overflow of a hpet counter, but that sounds off too). fwiw, there's quite a bit of variance in the delta that seems to show up. Clocksource tsc unstable (delta = -1010986453 ns) Clocksource tsc unstable (delta = -112130224777 ns) Clocksource tsc unstable (delta = -154880389323 ns) Clocksource tsc unstable (delta = -165033940543 ns) Clocksource tsc unstable (delta = -16610147135 ns) Clocksource tsc unstable (delta = -169783264218 ns) Clocksource tsc unstable (delta = -183044061613 ns) Clocksource tsc unstable (delta = -188697049603 ns) Clocksource tsc unstable (delta = -190100649573 ns) Clocksource tsc unstable (delta = -192732788150 ns) Clocksource tsc unstable (delta = -211622574067 ns) Clocksource tsc unstable (delta = -219378634234 ns) Clocksource tsc unstable (delta = -226609871873 ns) Clocksource tsc unstable (delta = -228355467642 ns) Clocksource tsc unstable (delta = -233950238702 ns) Clocksource tsc unstable (delta = -243666538341 ns) Clocksource tsc unstable (delta = -251535074315 ns) Clocksource tsc unstable (delta = -26880030622 ns) Clocksource tsc unstable (delta = -37899993747 ns) Clocksource tsc unstable (delta = -50471031780 ns) Clocksource tsc unstable (delta = -6821168015 ns) Clocksource tsc unstable (delta = -7067883139 ns) Clocksource tsc unstable (delta = -76682050692 ns) Clocksource tsc unstable (delta = -8296489689 ns) Clocksource tsc unstable (delta = -88373866635 ns) Clocksource tsc unstable (delta = -89099193219 ns) Clocksource tsc unstable (delta = -95946009388 ns) (sort -u'ed post grep, the ordering here doesn't mean anything) 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/