As title, this big commit is 117d783 bfs: VRQ solution v0.5
I think the most unstable issues in previous vrq release is caused by this and I believe most known issues(on my machines) have been fixed. It has been run stably for two weeks. So you are encouraged to have a try.
BUG: using smp_processor_id() in preemptible code, call trace from sys_sched_yield().
There still a few commits left I haven't reworked yet. I plan to finish them in two weeks before new kernel release and another sync-up cycle begins.