Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753431AbaD1FJv (ORCPT ); Mon, 28 Apr 2014 01:09:51 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:60074 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751252AbaD1FJs (ORCPT ); Mon, 28 Apr 2014 01:09:48 -0400 Message-ID: <1398661784.30930.33.camel@marge.simpson.net> Subject: Re: [ANNOUNCE] 3.14-rt1 From: Mike Galbraith To: Nicholas Mc Guire , Sebastian Andrzej Siewior Cc: linux-rt-users , LKML , Thomas Gleixner , rostedt@goodmis.org, John Kacur Date: Mon, 28 Apr 2014 07:09:44 +0200 In-Reply-To: <1398520699.28726.22.camel@marge.simpson.net> References: <20140411185739.GA6644@linutronix.de> <1397918766.5436.16.camel@marge.simpson.net> <1398411635.11930.45.camel@marge.simpson.net> <1398501491.12941.5.camel@marge.simpson.net> <1398520699.28726.22.camel@marge.simpson.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Nicholas, On Sat, 2014-04-26 at 15:58 +0200, Mike Galbraith wrote: > On Sat, 2014-04-26 at 10:38 +0200, Mike Galbraith wrote: > > On Fri, 2014-04-25 at 09:40 +0200, Mike Galbraith wrote: > > > > > Hotplug can still deadlock in rt trees too, and will if you beat it > > > hard. > > > > Box actually deadlocks like so. > > ... > > 3.12-rt looks a bit busted migrate_disable/enable() wise. > > /me eyeballs 3.10-rt (looks better), confirms 3.10-rt hotplug works, > swipes working code, confirms 3.12-rt now works. Yup, that was it. My boxen, including 64 core DL980 that ran hotplug stress for 3 hours yesterday with pre-pushdown rwlocks, say the migrate_disable/enable pushdown patches are very definitely busted. Instead of whacking selective bits, as I did to verify that the rwlock changes were indeed causing hotplug stress deadlock woes, I'm eyeballing the lot, twiddling primitives to look like I think they should, after which I'll let my boxen express their opinions of the result. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/