Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932081AbcDOTYc (ORCPT ); Fri, 15 Apr 2016 15:24:32 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35125 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753718AbcDOTXr (ORCPT ); Fri, 15 Apr 2016 15:23:47 -0400 Date: Fri, 15 Apr 2016 21:23:42 +0200 From: Daniel Vetter To: Gustavo Padovan , Daniel Vetter , Christian =?iso-8859-1?Q?K=F6nig?= , dri-devel , Linux Kernel Mailing List , Daniel Stone , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Riley Andrews , Rob Clark , Greg Hackmann , John Harrison , Laurent Pinchart , Sean Paul , =?iso-8859-1?Q?St=E9phane?= Marchesin , m.chehab@samsung.com, Maarten Lankhorst , Gustavo Padovan Subject: Re: [RFC 1/8] dma-buf/fence: add fence_collection fences Message-ID: <20160415192342.GY2510@phenom.ffwll.local> Mail-Followup-To: Gustavo Padovan , Christian =?iso-8859-1?Q?K=F6nig?= , dri-devel , Linux Kernel Mailing List , Daniel Stone , Arve =?iso-8859-1?B?SGr4bm5lduVn?= , Riley Andrews , Rob Clark , Greg Hackmann , John Harrison , Laurent Pinchart , Sean Paul , =?iso-8859-1?Q?St=E9phane?= Marchesin , m.chehab@samsung.com, Maarten Lankhorst , Gustavo Padovan References: <1460683781-22535-1-git-send-email-gustavo@padovan.org> <1460683781-22535-2-git-send-email-gustavo@padovan.org> <20160415080254.GQ2510@phenom.ffwll.local> <5710AE61.9040308@amd.com> <20160415182934.GB23954@joana> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20160415182934.GB23954@joana> X-Operating-System: Linux phenom 4.4.0-1-amd64 User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1298 Lines: 30 On Fri, Apr 15, 2016 at 11:29:34AM -0700, Gustavo Padovan wrote: > 2016-04-15 Daniel Vetter : > > > On Fri, Apr 15, 2016 at 11:03 AM, Christian K?nig > > wrote: > > > Might be that how amdgpu uses the fence context and sequence number is a bit > > > questionable, but this will completely break it. > > > > You mean it tries to qualesce fences in the same context down to just > > the last one? That's how it's supposed to be done, and > > fence_collections do break this somewhat. Without fixing up > > fence_is_later and friends. Sounds like amdgpu is a good use case to > > make sure the changes in semantics in these functions result in > > sensible code. In a way a fence_collection is a fence where the > > timeline never matches with any other timeline (since it's a > > combiation). > > > > And yeah I think fence_collection should probably compress down the > > fences to 1 per timeline. But then that's just an implementation > > detail we can fix later on. > > You mean asking for a new context for every collection? That would be one solution, but I fear it's a bit expensive. Having a special-case context for collections might be the better approach. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch