Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752807AbbHENTe (ORCPT ); Wed, 5 Aug 2015 09:19:34 -0400 Received: from arcturus.aphlor.org ([188.246.204.175]:42845 "EHLO arcturus.aphlor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751239AbbHENTd (ORCPT ); Wed, 5 Aug 2015 09:19:33 -0400 Date: Wed, 5 Aug 2015 09:18:57 -0400 From: Dave Jones To: Frederic Weisbecker Cc: Sasha Levin , paulmck@linux.vnet.ibm.com, Linux Kernel , Josh Triplett , Peter Zijlstra Subject: Re: 4.2-rc5 rcu stalls. Message-ID: <20150805131857.GA596@codemonkey.org.uk> Mail-Followup-To: Dave Jones , Frederic Weisbecker , Sasha Levin , paulmck@linux.vnet.ibm.com, Linux Kernel , Josh Triplett , Peter Zijlstra References: <20150803210835.GA4467@codemonkey.org.uk> <20150803213723.GN27280@linux.vnet.ibm.com> <20150803215535.GA13717@codemonkey.org.uk> <20150803220355.GO27280@linux.vnet.ibm.com> <55C0458B.6080003@oracle.com> <20150805001250.GA22259@codemonkey.org.uk> <20150805123757.GA7051@lerouge> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150805123757.GA7051@lerouge> User-Agent: Mutt/1.5.23 (2014-03-12) X-Spam-Score: -2.9 (--) X-Spam-Report: Spam report generated by SpamAssassin on "arcturus.aphlor.org" Content analysis details: (-2.9 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-Authenticated-User: davej@codemonkey.org.uk Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1661 Lines: 42 On Wed, Aug 05, 2015 at 02:37:59PM +0200, Frederic Weisbecker wrote: > On Tue, Aug 04, 2015 at 08:12:50PM -0400, Dave Jones wrote: > > On Tue, Aug 04, 2015 at 12:54:35AM -0400, Sasha Levin wrote: > > > On 08/03/2015 06:03 PM, Paul E. McKenney wrote: > > > >> > Ugh, that doesn't revert cleanly. Got something handy ? > > > > I do not, but perhaps either Sasha or Frederic do. > > > > > > I've attached a revert courtesy of Peter. > > > > Thanks. At first I thought this was doing the trick, but then I hit this again. > > > > > > [23643.545873] INFO: rcu_preempt detected stalls on CPUs/tasks: > > If it still happens after Sasha's revert, which basically revert all the offending > patches related to preempt lately, then the reason might be elsewhere. > > How hard was it to reproduce? I see 23000 secs in your dmesg logs which is around 6 hours. yeah. That's why I thought it had fixed it up until that point. My subsequent overnight run hit a different bug (that unpinning an unpinned lock bug in the scheduler) so I haven't had it happen since. > Also did you just launch trinity? no specific options? basically while [ 1 ]; do trinity -N 1000000 -q -l off -C256 -a64 -x fsync -x fdatasync -x syncfs -x sync -P INET --enable-fds=sockets sudo ipcrm -a done (The ipcrm thing is needed for long runs or eventually you oom, because trinity lacks the cleanup smarts) 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/