Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936944Ab3DJJa1 (ORCPT ); Wed, 10 Apr 2013 05:30:27 -0400 Received: from mail-ea0-f174.google.com ([209.85.215.174]:49170 "EHLO mail-ea0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752169Ab3DJJaY (ORCPT ); Wed, 10 Apr 2013 05:30:24 -0400 Date: Wed, 10 Apr 2013 11:33:22 +0200 From: Daniel Vetter To: Steven Rostedt Cc: Peter Zijlstra , Daniel Vetter , Maarten Lankhorst , linux-arch@vger.kernel.org, daniel.vetter@ffwll.ch, x86@kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, robclark@gmail.com, tglx@linutronix.de, mingo@elte.hu, linux-media@vger.kernel.org Subject: Re: [PATCH v2 2/3] mutex: add support for reservation style locks, v2 Message-ID: <20130410093322.GH27612@phenom.ffwll.local> Mail-Followup-To: Steven Rostedt , Peter Zijlstra , Maarten Lankhorst , linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, robclark@gmail.com, tglx@linutronix.de, mingo@elte.hu, linux-media@vger.kernel.org References: <20130228102452.15191.22673.stgit@patser> <20130228102502.15191.14146.stgit@patser> <1364900432.18374.24.camel@laptop> <515AF1C1.7080508@canonical.com> <1364921954.20640.22.camel@laptop> <1365076908.2609.94.camel@laptop> <20130404133123.GW2228@phenom.ffwll.local> <1365093662.2609.111.camel@laptop> <20130409222808.GC20739@home.goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130409222808.GC20739@home.goodmis.org> X-Operating-System: Linux phenom 3.7.0-rc4+ User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1410 Lines: 33 On Tue, Apr 09, 2013 at 06:28:08PM -0400, Steven Rostedt wrote: > On Thu, Apr 04, 2013 at 06:41:02PM +0200, Peter Zijlstra wrote: > > On Thu, 2013-04-04 at 15:31 +0200, Daniel Vetter wrote: > > > The thing is now that you're not expected to hold these locks for a > > > long > > > time - if you need to synchronously stall while holding a lock > > > performance > > > will go down the gutters anyway. And since most current > > > gpus/co-processors > > > still can't really preempt fairness isn't that high a priority, > > > either. > > > So we didn't think too much about that. > > > > Yeah but you're proposing a new synchronization primitive for the core > > kernel.. all such 'fun' details need to be considered, not only those > > few that bear on the one usecase. > > Which bares the question, what other use cases are there? Tbh I don't see any other either - but I agree with Peter and thinking things through and making the api a bit more generic seems to help in clarifying the semantics. Reminds me that I still need to draw a few diagrams ;-) -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- 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/