From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754405AbbCPN7P (ORCPT ); Mon, 16 Mar 2015 09:59:15 -0400 Received: from www.linutronix.de ([62.245.132.108]:35404 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751799AbbCPN7N (ORCPT ); Mon, 16 Mar 2015 09:59:13 -0400 Date: Mon, 16 Mar 2015 14:59:10 +0100 From: Sebastian Andrzej Siewior To: Steven Rostedt 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: <20150316135910.GA28130@linutronix.de> References: <20150312191307.081068717@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20150312191307.081068717@goodmis.org> X-Key-Id: 2A8CF5D1 X-Key-Fingerprint: 6425 4695 FFF0 AA44 66CC 19E6 7B96 E816 2A8C F5D1 User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * 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. With this patch applied FULL_NOHZ should not properly work (again) due to timer softirq wake ups (but this is a different problem). Sebastian