VRQ 0.2 release

As 3.17 will be released soon, earlier than it's expected, VRQ development is cut off and tagged for 0.2 release.

There are some bug fixes and others are improvement. Some is not related to VRQ locking, and I will see if it can be back-port to original BFS as baseline improvement in the next release. The detail changes are:

3ef882c bfs: Rework swap_sticky().
-- Yet another activity will be continued in next release.
e8754f9 bfs: rework resched_xxxx_idle(), basic version.
-- I will write another post to describe it in detail, but in brief, it rewrite the resched_xxxx_idle() using cpumask method.
2ae0fb6 bfs: refactory schedule() for rq&grq lock ctx switching.
cea6ce8 bfs: vrq: rq&grq locking ctx switch v3.
-- It's a bad idea to separate a context_switch process into two grq locking sessions, so I turn to this solution which hold rq and grq locking during context_switch.
319cd02 bfs: vrq, refactory wake_up_new_task.
79f5644 bfs: Fix need_other_cpu logic in schedule().
4d511fb bfs: RQ niffy solution.
-- Already described in previous post.
7c519a7 bfs: inlined routines update.

The test result are


50% Ratio:
5m19.531s
5m19.519s
5m19.509s
5m19.508s
5m19.430s
5m19.376s
5m19.363s
5m19.359s
5m19.333s
5m19.299s

150% Ratio:
2m54.394s
2m53.632s
2m51.960s
2m51.929s
2m51.925s
2m51.801s
2m51.790s
2m51.747s
2m51.641s
2m51.592s

100% Ratio:
2m51.001s
2m50.150s
2m49.881s
2m49.860s
2m49.812s
2m49.770s
2m49.764s
2m49.733s
2m49.699s
2m49.660s

100%+50% Ratio:
2m49.987s
2m49.980s
2m49.916s
2m49.865s
2m49.835s
2m49.828s
2m49.802s
2m49.784s
2m49.744s
2m49.733s

Comparing to vrq-02-baseline-test-result, under low or heavy workload, VRQ 0.2 shows a visible better throughput than the baseline. And under the optimize workload, VRQ 0.2 shows a slight better than baseline.

If you want have a try with VRQ 0.2, the code is located at v3.16.2-vrq.