From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752737Ab2GTPLp (ORCPT ); Fri, 20 Jul 2012 11:11:45 -0400 Received: from mga11.intel.com ([192.55.52.93]:14604 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751912Ab2GTPLn (ORCPT ); Fri, 20 Jul 2012 11:11:43 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.71,315,1320652800"; d="scan'208";a="181410892" Message-ID: <500974CD.7090804@linux.intel.com> Date: Fri, 20 Jul 2012 08:10:05 -0700 From: Darren Hart User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: Dave Jones , Thomas Gleixner , Linux Kernel , "Paul E. McKenney" , Rusty Russell , Darren Hart , Peter Zijlstra Subject: Re: 3.5-rc6 futex_wait_requeue_pi oops. References: <20120713180823.GA24972@redhat.com> <20120713185402.GA1707@redhat.com> <5008969F.5030901@linux.intel.com> <5008A847.4070006@linux.intel.com> <50090079.1000703@linux.intel.com> <20120720133501.GA30826@redhat.com> In-Reply-To: <20120720133501.GA30826@redhat.com> X-Enigmail-Version: 1.4.3 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/20/2012 06:35 AM, Dave Jones wrote: > On Thu, Jul 19, 2012 at 11:53:45PM -0700, Darren Hart wrote: > > > > >> I'll add a fix to that WARN_ON in my futex-fixes branch along with the > > >> fix for the bug Dan found. > > > > > > I think I have root cause. futex_wait_requeue_pi() doesn't like having > > > uaddr == uaddr2. The handle_early_wakeup() doesn't detect a problem > > > because key2 IS the same as key1, I think. I've just discovered this and > > > quickly hacked in a "if (uaddr==uaddr2) return -EINVAL" fix and the test > > > continues to run (with just ops 0, 11, 12) for several minutes now > > > (typically fails in a few seconds). I'll let it run for a few hours and > > > contemplate the proper fix. > > > > Dave, mind giving this a spin? It seems to be doing the trick here, > > at least for the *REQUEUE_PI futex op codes in trinity. > > Yeah, looks like that does the trick! It ran all night without an issue here too. I'll roll these up and send them out shortly. Dave, I love/hate trinity. ;-) -- Darren Hart Intel Open Source Technology Center Yocto Project - Linux Kernel