EXA performance problem

Maarten Maathuis madman2003 at gmail.com
Sun Nov 27 07:13:22 PST 2011

On Sun, Nov 27, 2011 at 3:55 PM, Christoph Bartoschek
<bartoschek at or.uni-bonn.de> wrote:
> Hi,
> I still have a huge performance problem with Xorg. One application that
> painted 2 Mio rectangles on the screen within a second or so with XFree86
> needs about a minute with Xorg.
> Most of the time is spent in libpixman. I've added some debug statements and
> see that pixman_raster_op is called about 7.2 mio times during my testcase.
> I do not think that pixman itself is the problem. It is just used too often
> by EXA.
> Is there anything I can do about this? Is there a better list where I can
> ask? Or do you know a person that might be interested in solving such a
> problem?
> Christoph
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As far as i know it basically boils down to this, rendering rectangles
is done in a software library as you observed. If your pixmap happens
to be outside normal ram then a lot of reads will kill performance.
These days the aim should be to use as little core rendering as
possible. A modern toolkit or a rendering library like cairo should
handle this far better.

Far away from the primal instinct, the song seems to fade away, the
river get wider between your thoughts and the things we do and say.

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