EXA performance problem

Christoph Bartoschek bartoschek at or.uni-bonn.de
Sun Nov 27 12:40:14 PST 2011

Am 27.11.2011 16:13, schrieb Maarten Maathuis:
> 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.

How can I check whether the pixmap is outside the normal ram? For me it 
does not look as if pixman is used for rendering the image. It looks as 
if EXA is managing the region that needs updates with pixman routines. 
But I could be wrong here.


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