From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Clifton Subject: Re: intel_prepare_render(intel); unhelpful? Date: Mon, 01 Nov 2010 22:19:34 +0000 Message-ID: <1288649974.2854.5.camel@pcjc2lap> References: <1288487734.3762.12.camel@pcjc2lap> <877hgxwvfp.fsf@pollan.anholt.net> <1288641178.21440.61.camel@pcjc2lap> <87wrowu7bp.fsf@pollan.anholt.net> <1288645484.2714.2.camel@pcjc2lap> <874oc0203e.fsf@pollan.anholt.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from ppsw-51.csi.cam.ac.uk (ppsw-51.csi.cam.ac.uk [131.111.8.151]) by gabe.freedesktop.org (Postfix) with ESMTP id 341FD9E78A for ; Mon, 1 Nov 2010 15:19:37 -0700 (PDT) In-Reply-To: <874oc0203e.fsf@pollan.anholt.net> 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: Eric Anholt , "intel-gfx@lists.freedesktop.org" List-Id: intel-gfx@lists.freedesktop.org On Mon, 2010-11-01 at 14:41 -0700, Eric Anholt wrote: > > I'm going to look at the case I "think" I hit an improvement for and > > dissect _why_, then get back to you. I'll check this again shortly.. (I recall I was testing this with the display lists anyway).. > > I'm chasing my code right now to see why it is emitting lots of batches > > when not using display lists for benchmarking purposes. I got my figures > > muddled up before.. I'm seeing 5 batches / frame when using Display > > lists, and nearer 40 when not. (I previously reported the other way > > around). > > I'd love to know too. INTEL_DEBUG=state (in the midst of much other > spam) dumps out a report of how many times various state changes got > flagged, which may highlight a change between the two modes. The large number of batches was due to a dumb dumb thing I was doing with VBOs.. rather than just discarding the memory after rendering some primitives, I was mapping the same VBO and re-uploading, causing synchronisation. Actually, I had two VBOs and was alternating between them, but was still of course causing synchronisation at the map stage. Fixed now, so my non display-list code is much faster again. I guess it kind of begs the question why the compiled display list needs 4 or 5 batches to do what my own code manages in 1. -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!) Tel: +44 (0)1223 748328 - (Shared lab phone, ask for me)