Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763424Ab3DDQqK (ORCPT ); Thu, 4 Apr 2013 12:46:10 -0400 Received: from merlin.infradead.org ([205.233.59.134]:54574 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762916Ab3DDQqI (ORCPT ); Thu, 4 Apr 2013 12:46:08 -0400 Message-ID: <1365093965.2609.116.camel@laptop> Subject: Re: [PATCH v2 2/3] mutex: add support for reservation style locks, v2 From: Peter Zijlstra 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 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" X-Mailer: Evolution 3.6.2-0ubuntu0.1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1117 Lines: 27 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 ;-) -- 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/