From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755133AbcB2PBm (ORCPT ); Mon, 29 Feb 2016 10:01:42 -0500 Received: from www.linutronix.de ([62.245.132.108]:40948 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752403AbcB2PBl (ORCPT ); Mon, 29 Feb 2016 10:01:41 -0500 Date: Mon, 29 Feb 2016 16:00:18 +0100 (CET) From: Thomas Gleixner To: Mike Galbraith cc: LKML , linux-rt-users , Sebastian Sewior , Steven Rostedt Subject: Re: [ANNOUNCE] v4.4.3-rt9 In-Reply-To: <1456756060.3488.120.camel@gmail.com> Message-ID: References: <1456756060.3488.120.camel@gmail.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 Mon, 29 Feb 2016, Mike Galbraith wrote: > On Mon, 2016-02-29 at 13:46 +0100, Thomas Gleixner wrote: > > Dear RT folks! > > > > I'm pleased to announce the v4.4.3-rt9 patch set. v4.4.2-rt7 and v4.4.3-rt8 > > are non-announced updates to incorporate the linux-4.4.y stable tree. > > > > There is one change caused by the 4.4.3 update: > > > > The relaxed handling of dump_stack() on RT has been dropped as there is > > actually a potential deadlock lurking around the corner. See: commit > > d7ce36924344 upstream. This does not effect the other facilities which > > gather stack traces. > > Hrm. I had rolled that dropped bit forward as below. I was given > cause to do a very large pile of ltp oom4 testing (rt kernels will > livelock due to waitqueue workers waiting for kthreadd to get memory to > spawn a kworker thread, while stuck kworker holds manager mutex, unless > workers are run as rt tasks to keep us from getting that depleted in > the first place), which gives it oodles of exercise, and all _seemed_ > well. Only seemed? Well, it will work nicely as long as you don't trigger a back trace in hard irq context. Hmm? Thanks, tglx