From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753442AbbCPOCS (ORCPT ); Mon, 16 Mar 2015 10:02:18 -0400 Received: from smtprelay0136.hostedemail.com ([216.40.44.136]:35826 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751247AbbCPOCO (ORCPT ); Mon, 16 Mar 2015 10:02:14 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::,RULES_HIT:41:355:379:541:599:800:960:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3352:3622:3865:3866:3867:3868:3870:3871:3872:3874:4321:5007:6261:7875:7901:10004:10400:10848:10967:11232:11658:11914:12043:12296:12517:12519:12740:13069:13311:13357:14096:14097:21080:21121,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: rate72_4ce246546aa05 X-Filterd-Recvd-Size: 2197 Date: Mon, 16 Mar 2015 10:02:05 -0400 From: Steven Rostedt To: Sebastian Andrzej Siewior Cc: linux-kernel@vger.kernel.org, linux-rt-users , Thomas Gleixner , Carsten Emde , John Kacur , Paul Gortmaker Subject: Re: [PATCH RT 00/39] Linux 3.14.34-rt32-rc1 Message-ID: <20150316100205.261c039e@gandalf.local.home> In-Reply-To: <20150316135910.GA28130@linutronix.de> References: <20150312191307.081068717@goodmis.org> <20150316135910.GA28130@linutronix.de> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 16 Mar 2015 14:59:10 +0100 Sebastian Andrzej Siewior wrote: > * Steven Rostedt | 2015-03-12 15:13:07 [-0400]: > > >Please scream at me if I messed something up. Please test the patches too. > > So Paul remided us about the dead lock thingy that has been reported. > Users reported that it does not occur with v3.18-RT and they think it is > due to 'Revert "timers: do not raise softirq unconditionally"' in > Revert-timers-do-not-raise-softirq-unconditionally.patch. > > I reverted it because I couldn't get highres to get to work at all on > v3.18 due to different synchronisation / expectaion of the timer > framework. Since the trylock might record a different lock owner it is > possible that this causes the deadlock (it thinks). Therefore it has no > stable tag nor any reference to the deadlock problem. I guess the question is, is there any other place that does a trylock in hard irq context? If so, the revert isn't going to fix it. -- Steve > > With this patch applied FULL_NOHZ should not properly work (again) due > to timer softirq wake ups (but this is a different problem). > > Sebastian