r300g and slow compositing in kwin

[MartinS]

Hello,

because I don't have any inside knowledge of the driver and I don't know what I should write as a bug report for mesa I'm posting this here:

KWin is really slow when using OpenGL compositing. I've posted a bug report here: https://bugs.kde.org/show_bug.cgi?id=253903
One problem could be because the driver reports that NPOT is supported, when in fact it is not. So perhaps someone who knows the driver can answer Martin Gr??lin (or give an answer here and I will post the answer in the bug report) if the driver really supports NPOT.

It would be really nice to find out what the performance bottle neck for compositing in kwin is, as compositing is currently in an unusable state for r300g.

[rohcQaH]

I think the issue was that your hardware generation supports npot only partially, IIRC mipmapped npot textures didn't work.

Since many apps rely on npot and the major use case for npot textures is framebuffers/render targets (-> non-mipmapped), the extension is exported anyway.

I don't know if kwin wants to create mipmaps before rendering the window..

[MartinS]

Thanks for your feedback. I've posted your reply to the bug report.

[PapadakosPanagiotis]

Fixed in 4.6 svn

This is the bug https://bugs.kde.org/show_bug.cgi?id=256654

and this is the kwin diff:

Don't specify the texture target explicitly with r300g.

This is reported to cause a performance regression.

http://websvn.kde.org/branches/KDE/4.6/kdebase/workspace/kwin/scene_opengl.cpp?r1=1215519&r2=1215518&pathrev=1215519

Any developer can comment on this?

[PapadakosPanagiotis]

Missed the 1 minute edit...
Maybe it also helps https://bugs.kde.org/show_bug.cgi?id=253903

This is the bug https://bugs.kde.org/show_bug.cgi?id=256654

and this is the kwin diff:

Don't specify the texture target explicitly with r300g.

This is reported to cause a performance regression.

http://websvn.kde.org/branches/KDE/4.6/kdebase/workspace/kwin/scene_opengl.cpp?r1=1215519&r2=1215518&pathrev=1215519

Any developer can comment on this?