https://bugs.freedesktop.org/show_bug.cgi?id=110214
--- Comment #67 from Marek Olšák maraeo@gmail.com --- (In reply to Michel Dänzer from comment #63)
(In reply to Diego Viola from comment #62)
export MESA_EXTENSION_OVERRIDE="-GL_NV_texture_barrier"
This helps alleviate the problem (xterm does not have the issue with this), however, the problem is still present in Xephyr.
To clarify, you mean Xephyr from xserver 1.16 here (where glamor didn't make use of GL_NV_texture_barrier yet), disabling GL_NV_texture_barrier helps with current Xephyr, right?
It seems like DPBB needs to be disabled when glTextureBarrier(NV) is called, otherwise primitives may be reordered across the barrier. Does that make sense, Marek?
Primitives aren't reordered with DPBB. Primitives can't also survive a barrier with DPBB. DPBB has no effect on behavior, it just changes how PS wavefronts are formed.