Keith Packard Exploring "Semi-Automatic Compositing" For The X.Org Server
Keith is broadly working on trying to improve composite acceleration within the X.Org Server to reduce the number of copies needed to get an application's contents to the screen, being able to get the screen contents delivered on time and for the application to know that, and to improve this overall process.
With timing being key in virtual reality to avoid motion sickness and the like, in cooperation with Valve he's working on making it possible so the Steam VR compositor would be able to reliably present content at known times and for knowing when that content was presented. Keith had previously been working on an "automatic compositing" idea but for easing integration for existing X window managers to support it, he is now pursuing a "semi-automatic compositing" approach.
If you are interested in learning all the technical details about this new semi-automatic compositing plan, see the KeithP.com blog for all the details. This plan is still in the early stages and he is collecting feedback and trying to figure out if his design is workable, so stay tuned for more.