From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicholas Mc Guire Subject: Re: [ANNOUNCE] 3.12.6-rt9 Date: Fri, 27 Dec 2013 21:00:24 +0100 Message-ID: <20131227200024.GA19505@opentech.at> References: <20131223225017.GA8623@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-rt-users , LKML , Thomas Gleixner , rostedt@goodmis.org, John Kacur To: Sebastian Andrzej Siewior Return-path: Content-Disposition: inline In-Reply-To: <20131223225017.GA8623@linutronix.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org On Mon, 23 Dec 2013, Sebastian Andrzej Siewior wrote: > Dear RT folks! > > I'm pleased to announce the v3.12.6-rt9 patch set. > > Changes since v3.12.6-rt8 > - A patch from Thomas Gleixner not to raise the timer softirq > unconditionally (only if a timer is pending) > This one seems to deadlock early in the boot sequence on x86 (i3/i7/Phenom-4x here and Carsten Emde also had boot failures) after droping this patch with: patch -p1 -R < ../paches/timers-do-not-raise-softirq-unconditionally.patch 3.12.6-rt9 boots up fine. cyclictest seems to be back to what it was before (only ran for a few minutes idle and 1h with load on an i3). The main problem with this patch though are proceduaral isues the commit note - which is a mail exchange - actually does not explain what the rational for the changes is (...well I don't understand the logic of run_local_timers - if someone can explain - pleas do) and notably: from timers-do-not-raise-softirq-unconditionally.patch well, that very same problem is in mainline if you add "threadirqs" to the command line. But we can be smart about this. The untested patch ^^^^^^^^^^^^^^^^^^ below should address that issue. If that works on mainline we can adapt it for RT (needs a trylock(&base->lock) there). does make me wonder why this went into -rt9 ? It also build fails with CONFIG_PREEMPT_RT_FULL not set. as with this patch, systems that booted just fine with 3.12.5-rt7 don't even boot (atleast my 3 x86 test boxes here did not) this raises some questions regarding the process of getting patches into -rtX - are we going to fast here ? I would prefere if such patches would go out with a request for testing or atleast a "might blow up your system" note in them... thx! hofrat