Performance change from X in Fedora Core 4 to Fedora Core 5

Clemens Eisserer linuxhippy at gmail.com
Sun Jul 9 12:48:49 PDT 2006


For me GTKs performance also got that bad (and my whishes to the list
had not been heard) that I got my hands on GTKs code.

I did some profiling on my NVidia based systems and it turned out that
GDK's backbuffering was problematic - at each expose GDK was creating
several large pixmaps, drawing into them, paint them a single time and
then release it.

I hacked a bit inside of GTK-2.9.4 and some things are still broken
(spinner widget, firefox's checkboxes - don't know why but if you find
out please let me know!) but its quite stable. Sice GTK-2.10 is
basically 2.9.5 I guess it should be enough just to copy these files
into GTK-2.10 source and rebuild it:
http://web460.server3.webplus24.de/gdkwindow.c
http://web460.server3.webplus24.de/gdkwindow.h
http://web460.server3.webplus24.de/gtkwindow.c
http://web460.server3.webplus24.de/gtkwindow.h
If something is missing please let me know ;-)

However its implementation is an ugly hack - I don't recommend it for
anything than profiling!
Maybe someone whos interrested can try it out (in conjunction with
gtkperf for example), I got a speedup of 35% in gtkperf, some
operations are up to 5x faster.
Whats still very bad is the expose of complex widgets like trees,
lists or tables.

I would be happy to get some other before/after results of machines
with different cards/drivers and maybe suggestions how to do it in a
better way. For now I only wrote C at school ;)

lg Clemens

Roo: Whats next? Do you send Linus a mail asking him to put his hands
on GTK because desktop users get a bad impression of Linux on Desktop
in general.
Furthermore please stop spreading FUD about other projects and people,
thats a do-not - especially if you would like to have something from
the guys you badmouth in public!



More information about the xorg mailing list