From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: Re: [ANNOUNCE] v4.4.3-rt9 Date: Mon, 29 Feb 2016 16:09:39 +0100 Message-ID: <1456758579.3488.125.camel@gmail.com> References: <1456756060.3488.120.camel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: LKML , linux-rt-users , Sebastian Sewior , Steven Rostedt To: Thomas Gleixner Return-path: Received: from mail-wm0-f54.google.com ([74.125.82.54]:35842 "EHLO mail-wm0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754403AbcB2PJo (ORCPT ); Mon, 29 Feb 2016 10:09:44 -0500 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Mon, 2016-02-29 at 16:00 +0100, Thomas Gleixner wrote: > 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? Poo.. that's a pretty darn good reason. Thanks. -Mike