[sugar] rendering test

[Jordan Crouse]

On 28/09/08 18:46 +0200, Bernie Innocenti wrote:
> Tomeu Vizoso wrote:
> > Ooops. cc'ing to some other people/list in the hope someone more
> > knowledgeable than me will comment.
> 
> Thanks.  Please Cc me on posts like these to make sure I don't miss them. 
>   No, it doesn't bother me to receive 0.001% more mail.
> 
> I've also Cc'd the Xorg list in case someone can give us more insight.
> 
> 
> > On Sun, Sep 28, 2008 at 12:46 PM, Riccardo Lucchese
> > <riccardo.lucchese at gmail.com> wrote:
> >> On Sun, 2008-09-28 at 12:43 +0200, Riccardo Lucchese wrote:
> >>> * build 703, xorg driver = amd, redraws = 200
> >>> - pixbuf:
> >>>   98.63s
> >>>   96.96s
> >>>   96.58s
> >>>   97.14s
> >>>   99.21s
> >>>
> >>> * build 703, xorg driver = fbdev, redraws = 200
> >>> - pixbuf:
> >>>   55.81s
> >>>   55.40s
> >>>   55.22s
> >>>   55.50s
> >>>   55.63s
> >>>
> >>> * build 2489, xorg driver = amd, redraws = 200
> >>> - pixbuf:
> >>>   84.21s
> >>>   84.81s
> >>>   81.94s
> >>>   81.79s
> >>>   85.29s
> >>>
> >>> * build 2489, xorg driver = fbdev, redraws = 200
> >>> - pixbuf:
> >>>   62.83s
> >>>   62.81s
> >>>   62.81s
> >>>   62.66s
> >>>   63.14s
> >>>
> >>> - joyride regressed sensibly at rendering with cairo since 703
> >>> - rendering pixbufs is extremely slow on the xo
> >>> - server side surfaces are awesome ;)
> >>>
> >> and btw why is fbdev faster than the geode driver at rendering pixbufs ?
> 
> Was fbdev running with EXA or XAA?  (does fbdev even support EXA?)
> 
> My performance tests with X 1.3 and 1.4 had shown that turning on EXA 
> makes many operations slower.  It's hard to tell why, but it might have to 
> do with loosing XShmPut() (MIT shared memory), excessive migration of 
> pixmaps to the framebuffer, and so on.  X 1.5 was supposed to have a much 
> better EXA, at least judging from the stream of patches landed on the tree.

Indeed - migration is probably what is hurting us the most here.   We 
would probably have to do a more in-depth analysis of what is actually
happening in the engine, but the general rule of thumb is that it is very
very very very very bad to read from the video memory. 

Jordan

(Did I mention it was bad?)

-- 
Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.