From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753195AbZHHXLz (ORCPT ); Sat, 8 Aug 2009 19:11:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753129AbZHHXLy (ORCPT ); Sat, 8 Aug 2009 19:11:54 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:47518 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753058AbZHHXLx (ORCPT ); Sat, 8 Aug 2009 19:11:53 -0400 Message-ID: <4A7E0631.7000205@us.ibm.com> Date: Sat, 08 Aug 2009 16:11:45 -0700 From: Darren Hart User-Agent: Thunderbird 2.0.0.22 (X11/20090608) MIME-Version: 1.0 To: Ingo Molnar CC: Peter Zijlstra , "lkml," , linux-rt-users , Thomas Gleixner , Steven Rostedt , John Kacur , Dinakar Guniguntala , John Stultz Subject: Re: [RFC][PATCH] fixup pi_state in futex_requeue on lock steal References: <4A7A1D48.7040309@us.ibm.com> <1249576660.32113.585.camel@twins> <4A7B5D46.7080109@us.ibm.com> <20090808152756.GH28892@elte.hu> In-Reply-To: <20090808152756.GH28892@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: > * Darren Hart wrote: > >> So, I think we're fine with respect to the pi_state ownership! In >> fact I finally managed to catch the lock steal in the requeue loop >> in my tracing, and everything worked fine. Going to go rerun a >> bunch more tests and see if I hit any other issues, if I do, I >> suspect they are unrelated to this. >> >> Thanks for the help in thinking this through. > > i've got these queued up: > > 00235fe: futex: Update woken requeued futex_q lock_ptr > 1bbf208: rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock() > > should i drop them? My apologies for the churn on these Ingo. My comments above only apply to this RFC thread, the other patches are needed. You should include the following patches: tip/core/urgent =============== rtmutex: Avoid deadlock in rt_mutex_start_proxy_lock() 1bbf20835c4e088667a090ce6523a0f70b62dc76 [PATCH] futex: Update futex_q lock_ptr on requeue proxy lock (resend) from Aug 7, 2009 The one you committed is older, I resent it on Aug 7 with an improved patch description, commentary, and DEBUG_PI_LIST ifdefs. Please drop 00235fe25eba6d3a13f3349b2e3a2d94b699a414 and pull in the new one. [PATCH V2] futex: Fix handling of bad requeue syscall pairing from Aug 7, 2009 tip/rt/something ================ [PATCH 2/2][RT] Avoid deadlock in rt_mutex_start_proxy_lock() from Aug 5, 2009 This one uses the new atomic_spinlock calls for the RT tree. I suspect you may instead choose to make that one line change yourself. Thanks, -- Darren Hart IBM Linux Technology Center Real-Time Linux Team