The adaptive tickless kernel support ended up being a big endeavour as well as getting other kernel developers to review the patches.
In a new status update from Frederic Weisbecker, he writes, "So the process seem to be in a better direction now. Summer holidays have naturally made it a bit smoother and the rythm will probably stay that way until the end of ksummit/linuxcon/LPC. But I have the feeling we are moving forward. No schedule plans, but once I get the above topics sorted out, I'll probably work on timekeeping handling in adaptive tickless CPUs. And then the rest..."