Re: Notes on wip/gdk-gl2

[Alexander Larsson <alexl redhat com>]

On sön, 2014-10-12 at 18:47 -0400, Owen Taylor wrote:
> Performance on my system is actually quite poor in at the moment, which
> seems at least to be pathological interactions with the system
> (i915, Fedora 21, Haswell.) I see 60fps with the default configuration
> of gdkgears for any windowed size of the window, but when I maximize I
> see the frame rate drop to 30fps, and when I make it fullscreen, I see
> it drop to 10fps. 'perf top' shows kernel memory allocation as the top
> functions, so it may be that the continual allocation of new render
> buffers is triggering the problem.

I've done a lot of changes to how the glarea works and how the internal
gl machinery works. I'm seeing a lot better performance than this, can
you try it again and see how the current code performs?

> I also see rendering locked at a sub-multiples of 60fps - despite the
> fact that the rendering is additionally synchronized with the compositor
> frame clock. If I export vblank_mode=0 I see the expected non-locking
> behavior.

How exactly do you see this?