From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: Improvements and fixes for Intel ddx swap scheduling/timestamping. Date: Mon, 8 Oct 2012 10:00:47 +0200 Message-ID: <20121008080047.GA6116@phenom.ffwll.local> References: <1349591890-13732-1-git-send-email-mario.kleiner@tuebingen.mpg.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wi0-f177.google.com (mail-wi0-f177.google.com [209.85.212.177]) by gabe.freedesktop.org (Postfix) with ESMTP id D6D7F9E889 for ; Mon, 8 Oct 2012 01:00:04 -0700 (PDT) Received: by mail-wi0-f177.google.com with SMTP id hj13so2718960wib.12 for ; Mon, 08 Oct 2012 01:00:04 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1349591890-13732-1-git-send-email-mario.kleiner@tuebingen.mpg.de> 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: Mario Kleiner Cc: daniel.vetter@ffwll.ch, intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Sun, Oct 07, 2012 at 08:38:07AM +0200, Mario Kleiner wrote: > Hi, > > a series of three patches to improve the dri2 swap scheduling > and timestamping for the current intel ddx. > > The first one enables proper OML_sync_control timestamping > while triple-buffering is enabled and XOrg 1.12+ with DRI2SwapLimit > support is in use. So far, timestamping was unuseable with > triple-buffering, only worked with double-buffering. > > The second one repairs the broken pageflip swap scheduling, which > is apparently in a frightening state for timing sensitive apps > since a year, due to a tiny but really ugly bug. In a perfect > implementation of Murphy's law, the same commit that broke the > scheduling also disabled the builtin correctness checks that > were supposed to catch such bugs. > > The third one proposes to revert 'SwapBuffersWait' to its old > behaviour where it didn't affect pageflipping. I just can't > think of a case where the current behaviour makes any sense, not > even for benchmarking? But maybe i'm overlooking something. > > All patches were tested against an Intel 945-GME gpu. > > I don't really care about the 'SwapBuffersWait' patch one way > or the other, but the first two are crucial to make the intel > ddx useable in a painless and safe way again for users of > timing sensitive applications. This kind of regressions suck. Are there no tests (in piglit) that check OML buffer swap and timestamping behaviour at least internally? Or could I volunteer you to create that? Toghether with the new kernel flip tests this should catch any further such regressions ... -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch