From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [PATCH v2 2/3] mutex: add support for reservation style locks, v2 Date: Tue, 9 Apr 2013 18:28:08 -0400 Message-ID: <20130409222808.GC20739@home.goodmis.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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:20883 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754795Ab3DIW2K (ORCPT ); Tue, 9 Apr 2013 18:28:10 -0400 Content-Disposition: inline In-Reply-To: <1365093662.2609.111.camel@laptop> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Peter Zijlstra Cc: 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 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? -- Steve