Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757713AbaGWJzj (ORCPT ); Wed, 23 Jul 2014 05:55:39 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:47948 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752272AbaGWJzi (ORCPT ); Wed, 23 Jul 2014 05:55:38 -0400 Message-ID: <53CF8693.1040006@canonical.com> Date: Wed, 23 Jul 2014 11:55:31 +0200 From: Maarten Lankhorst User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: =?UTF-8?B?Q2hyaXN0aWFuIEvDtm5pZw==?= , Daniel Vetter , =?UTF-8?B?Q2hyaXN0aWFuIEvDtm5pZw==?= CC: Thomas Hellstrom , nouveau , LKML , dri-devel , Ben Skeggs , "Deucher, Alexander" Subject: Re: [Nouveau] [PATCH 09/17] drm/radeon: use common fence implementation for fences References: <20140709093124.11354.3774.stgit@patser> <53CE8A57.2000803@vodafone.de> <53CF58FB.8070609@canonical.com> <53CF5B9F.1050800@amd.com> <53CF5EFE.6070307@canonical.com> <53CF63C2.7070407@vodafone.de> <53CF6622.6060803@amd.com> <53CF699D.9070902@canonical.com> <53CF6B18.5070107@vodafone.de> <53CF7035.2060808@amd.com> <53CF7191.2090008@canonical.com> <53CF765E.7020802@vodafone.de> <53CF8010.9060809@amd.com> <53CF822E.7050601@amd.com> <53CF84C7.2020507@vodafone.de> In-Reply-To: <53CF84C7.2020507@vodafone.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org op 23-07-14 11:47, Christian König schreef: > Am 23.07.2014 11:44, schrieb Daniel Vetter: >> On Wed, Jul 23, 2014 at 11:39 AM, Daniel Vetter wrote: >>> The scheduler needs to keep track of a lot of fences, so I think we'll >>> have to register callbacks, not a simple wait function. We must keep >>> track of all the non-i915 fences for all oustanding batches. Also, the >>> scheduler doesn't eliminate the hw queue, only keep it much slower so >>> that we can sneak in higher priority things. >>> >>> Really, scheduler or not is orthogonal. >> Also see my other comment about interactions between wait_fence and >> the i915 reset logic. We can't actually use it from within the >> scheduler code since that would deadlock. > > Yeah, I see. You would need some way to abort the waiting on other devices fences in case of a lockup. > > What about an userspace thread to offload waiting and command submission to? You would still need enable_signaling, else polling on the dma-buf wouldn't work. ;-) Can't wait synchronously with multiple shared fences, need to poll for that. And the dma-buf would still have fences belonging to both drivers, and it would still call from outside the driver. ~Maarten -- 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/