[sugar] rendering test

[Riccardo Lucchese]

On Sun, 2008-09-28 at 18:46 +0200, Bernie Innocenti wrote:
> >>> - 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?)
http://www.x.org/wiki/ExaStatus lists fbdev in the `Probably unsuitable
for EXA support' section; so, I guess XAA.

> 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.
> 
> I'd be very interested in seeing the output of oprofile while running your 
> benchmark on X 1.4 and X 1.5.  Please, remember to install the debuginfo 
> packages for the X server, libcairo, and the geode driver.

I haven't tried to run oprofile on the xo yet (it is on my todo list).

If I remember well, ExaDoMoveOutPixmap (or a function with a similar
name) and memcpy were always on top of sysprof profiles in rendering
tests.

riccardo