Comment 19 for bug 1037411

(In reply to comment #2)
> I call glCopyPixels a couple of times briefly on startup and then never again.
> The problem is that doing this makes all subsequent rendering much slower. If I
> never call glCopyPixels on startup then rendering remains fast thereafter.

What are the read and draw buffers for glCopyPixels? If either of them is GL_FRONT*, that will cause a DRI2 fake front buffer to be allocated and thereafter kept up to date wrt the real front buffer.

> This seems to set a flag in the ctx which is never cleared.

It is cleared:

   _mesa_set_vp_override(ctx, GL_FALSE);