From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maarten Lankhorst Subject: Re: Synchronization framework Date: Thu, 07 Jun 2012 10:55:45 +0200 Message-ID: <4FD06C91.6020507@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-ey0-f177.google.com (mail-ey0-f177.google.com [209.85.215.177]) by gabe.freedesktop.org (Postfix) with ESMTP id A135B9E7E4 for ; Thu, 7 Jun 2012 01:55:48 -0700 (PDT) Received: by eaaf11 with SMTP id f11so158411eaa.36 for ; Thu, 07 Jun 2012 01:55:47 -0700 (PDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org To: Erik Gilling Cc: linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org Hey, For intel/nouveau hybrid graphics I'm interested in this since it would allow me to synchronize between intel and nvidia cards without waiting for rendering to complete. I'm worried about the api though, nouveau and intel already have existing infrastructure to deal with fencing so exposing additional ioctl's will complicate the implementation. Would it be possible to never expose this interface to userspace but keep it inside the kernel only? nouveau_gem_ioctl_pushbuf is what's used for nouveau. If any dmabuf synch framework could hook into that then userspace would never have to act differently on shared bo's. I haven't looked at intel and amd, but from a quick glance it seems like they already implement fencing too, so just some way to synch up the fences on shared buffers seems like it could benefit all graphics drivers and the whole userspace synching could be done away with entirely. Cheers, Maarten