From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 16/16] drm/i915: Introduce mapping of user pages into video memory (userptr) ioctl Date: Sat, 01 Dec 2012 11:25:22 +0000 Message-ID: <275ffc$7ljsuj@fmsmga002.fm.intel.com> References: <1352979151-9934-1-git-send-email-chris@chris-wilson.co.uk> <1352979151-9934-17-git-send-email-chris@chris-wilson.co.uk> <20121130230643.GE4384@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTP id 08D3CE5EAC for ; Sat, 1 Dec 2012 04:50:25 -0800 (PST) In-Reply-To: <20121130230643.GE4384@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Sat, 1 Dec 2012 00:06:43 +0100, Daniel Vetter wrote: > Quick review: > - I don't like the internal byte offset we add/substract for relocations. > mmap works on page boundaries, imo gpu mmap should do the same. However, the necessity is that I work on unaligned boundaries since I have no control over how the clients allocate the memory to be mapped, or which bytes within that memory are associated with a particular pixmap. The XShm API is such that not even the ShmSegment is passed down to the driver. That vies with the lack of explicit synchronisation points as being the worst elements of its design. -Chris -- Chris Wilson, Intel Open Source Technology Centre