Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938689AbcKWOda (ORCPT ); Wed, 23 Nov 2016 09:33:30 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:41198 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938680AbcKWOcG (ORCPT ); Wed, 23 Nov 2016 09:32:06 -0500 Date: Wed, 23 Nov 2016 15:32:00 +0100 From: Peter Zijlstra To: Nicolai =?iso-8859-1?Q?H=E4hnle?= , Nicolai =?iso-8859-1?Q?H=E4hnle?= , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Ingo Molnar , stable@vger.kernel.org, Maarten Lankhorst Subject: Re: [PATCH 1/4] locking/ww_mutex: Fix a deadlock affecting ww_mutexes Message-ID: <20161123143200.GV3092@twins.programming.kicks-ass.net> References: <1479900325-28358-1-git-send-email-nhaehnle@gmail.com> <20161123140336.GU3092@twins.programming.kicks-ass.net> <20161123142525.ns2pkyp4bo2sa5z2@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161123142525.ns2pkyp4bo2sa5z2@phenom.ffwll.local> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 325 Lines: 7 On Wed, Nov 23, 2016 at 03:25:25PM +0100, Daniel Vetter wrote: > Without thinking it through in detail this is a PI issue, except that we > replace boosting with wakeup&back-off. Could we perhaps steal something > from rt mutexes to make it fair&efficient? rt_mutexes order the waiters by 'priority' and wake the top most.