https://bugs.freedesktop.org/show_bug.cgi?id=106175
--- Comment #87 from Brandon Wright bearoso@gmail.com --- It's important to distinguish between when the compositor and application desync and when there's actually a driver hiccup.
If the compositor and application swaps get switched around briefly, it'll produce stutter, but this won't be reflected on the vsynctester graph (it'll stay green). If it's red, that means the the application missed a frame. The former is strictly the compositor's fault.