From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH v2 2/3] mutex: add support for reservation style locks, v2 Date: Thu, 04 Apr 2013 18:46:05 +0200 Message-ID: <1365093965.2609.116.camel@laptop> 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> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130404133123.GW2228@phenom.ffwll.local> Sender: linux-kernel-owner@vger.kernel.org To: Daniel Vetter Cc: 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 List-Id: linux-arch.vger.kernel.org On Thu, 2013-04-04 at 15:31 +0200, Daniel Vetter wrote: > I'm a bit confused about the different classes you're talking about. > Since > the ticket queue is currently a global counter there's only one class > of > ww_mutexes. Right, so that's not something that's going to fly.. we need to support multiple users, including nesting of those. Again, you're adding something to the generic kernel infrastructure, it had better be usable :-) > I guess we could change that once a second user shows up No, we fix that before it all goes in. I would _so_ hate to find out it cannot be 'fixed' and be stuck with a half-arsed sync primitive in the core kernel that's only every usable by the one existent user. So for now, forget all about TTM, DMA-BUF and other such coolness except to verify that whatever we end up with does indeed work for the case you need it for ;-) From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from 173-166-109-252-newengland.hfc.comcastbusiness.net ([173.166.109.252]:52458 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763183Ab3DDQqR (ORCPT ); Thu, 4 Apr 2013 12:46:17 -0400 Received: from dhcp-089-099-019-018.chello.nl ([89.99.19.18] helo=dyad.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.80.1 #2 (Red Hat Linux)) id 1UNnIm-0007CF-NJ for linux-arch@vger.kernel.org; Thu, 04 Apr 2013 16:46:17 +0000 Message-ID: <1365093965.2609.116.camel@laptop> Subject: Re: [PATCH v2 2/3] mutex: add support for reservation style locks, v2 From: Peter Zijlstra Date: Thu, 04 Apr 2013 18:46:05 +0200 In-Reply-To: <20130404133123.GW2228@phenom.ffwll.local> 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> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Daniel Vetter Cc: 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 Message-ID: <20130404164605.icR6QMJngHoMADDUT5SHC6AZKhG7Dq0yqUgpGe-GPMw@z> On Thu, 2013-04-04 at 15:31 +0200, Daniel Vetter wrote: > I'm a bit confused about the different classes you're talking about. > Since > the ticket queue is currently a global counter there's only one class > of > ww_mutexes. Right, so that's not something that's going to fly.. we need to support multiple users, including nesting of those. Again, you're adding something to the generic kernel infrastructure, it had better be usable :-) > I guess we could change that once a second user shows up No, we fix that before it all goes in. I would _so_ hate to find out it cannot be 'fixed' and be stuck with a half-arsed sync primitive in the core kernel that's only every usable by the one existent user. So for now, forget all about TTM, DMA-BUF and other such coolness except to verify that whatever we end up with does indeed work for the case you need it for ;-)