https://bugs.freedesktop.org/show_bug.cgi?id=79850
--- Comment #7 from Sylvain BERTRAND sylvain.bertrand@gmail.com --- done.
can_flip returns true.
Check with the first linux 3.16, vsync still does not want to be enabled in dota2, and still the front and backbuffer swap is clearly visible in awesomenauts with vsync enabled.