Cairo's slow rendering on XO-1 (was: olpcgames - mainloop bug help)

[Mart Raudsepp]

On R, 2010-06-25 at 22:49 -0400, Wade Brainerd wrote:
> That said I see in a later post that you switched to GTK/Cairo which
> is great - so long as you don't get too bogged down by Cairo's slow
> rendering on XO-1.

Any such slowness should be fixed at the root - the xf86-video-geode
driver - instead of avoiding GTK/cairo specifically due to that.
Unless heavily targeting existing system roll-outs without upgrading of
the system, I suppose.


While we do already have our work ahead of us in optimizing the standard
cairo benchmarks (found in the cairo-traces repository), concrete cases
that would benefit the applications used specifically on the XO-1 would
be appreciated. Fixing things that can potentially make 1.5 million kids
happier can be a great motivator.

Ideally this would be presented as a cairo-trace recording as per
http://cairographics.org/FAQ/#profiling but I do have a OLPC XO-1 and
other Geode LX systems to generate that myself if that's too complex
(currently that cairo-trace is only in the development version, and not
installed outside build tree), given a description of what
program/activity exactly is way too slow and while doing what exactly in
that program.

Such reports can be sent to freedesktop bugzilla under the Driver/geode
component of xorg product, or the xorg-driver-geode mailing list over at
http://lists.x.org/mailman/listinfo/xorg-driver-geode
Personally to me is also fine, and maybe also good as I can apply some
filtering and identify the slow routines beforehand.
We also hang out on FreeNode IRC channel #geode
More information on http://wiki.x.org/wiki/GeodeDriver


Currently we (primarily two AMD employees, not so much me) are
concentrating on fixing some of the awful bugs (many of which get
triggered only by a newer xorg-server version), such as misrendering
with HwAccel and rotation issues. After those are hopefully fixed soon,
some attention will probably start to go on hardware acceleration
performance, as the current situation is indeed rather sad:
http://people.freedesktop.org/~leio/geode/perf/


-- 
Mart Raudsepp
Gentoo Developer, xf86-video-geode contributor
Mail: leio at gentoo.org