[PATCH weston v3 4/4] gl-renderer: Emit GPU rendering begin and end timeline timepoints

[Chris Wilson]

Quoting Alexandros Frantzis (2017-09-27 13:09:16)
> Use EGL fence sync objects to emit timepoints for the beginning and the
> end of rendering on the GPU.

But why not use a qbo with GL_TIMESTAMP?

sync_file are only timestamped when they are signaled, which is very,
very loosely coupled with the GPU rendering. Each will also force a
flush and submission of the GL pipeline, which seems to me to be very
heavyweight ?
-Chris