Re: Full screen GtkDrawingArea performance sucking - help me!

[Alex Jones <alex weej com>]

On Mon, 2007-08-27 at 14:47 +0200, Sven Herzberg wrote:
> Alex Jones wrote:
> > Hi list
> >
> > In my quest to write an awesome backdrop rendering app, I have this test
> > program that draws random colours to a GtkDrawingArea. For me, any size
> > over about 300x300 at 60fps just causes insane lag in Xorg -- the
> > renderings seem to queue up. If I run cairo clock maximised full screen,
> > it literally LAGS by about 5 seconds. Telling it to close takes ages, as
> > if the X connection is completely saturated. My own cairo clock which
> > draws the second hand smoothly between intervals shows that it seems to
> > run at less-than-real-time, but still smoothly. Eventually, the clock
> > skips ahead by 10 seconds or so.
> >
> > I have a 2.8 GHz Pentium 4 with 1 GB of RAM, nothing using my CPU and a
> > Radeon 9800 Pro with the r200 drivers. What's going on? This is a total
> > spanner-in-the-works for me.
> >   
> 
> Please open $YOUR_FAVORITE_PROFILER and provide some proof that your
> issues are related to GTK+.

I don't have a favourite profiler. Suggest me one! (And show me how to
use it :P)

I believe it's something wrong with either GTK, Cairo or XRender because
it's apparent that the expose event handler is running in good time, but
the XRender operations are just queueing up like mad on the server until
it spills over and discards a load of them. I don't think a clock should
render like this. Finding the perfect framerate thus becomes a case of
finding a magic number for a specific system in a specific condition,
unless I'm missing something.