[no subject]

[Dave Chiluk]

Changelog v4
 - Rewrote patch to return all quota when cfs_b has very litte.
 - Removed documentation changes, as bursting is no longer possible with this
   new solution.

After the suggestion from Ben Segall to set min_cfs_rq_runtime=0, I came up
this in an attempt to balance the desire leave runtime on the per-cpu queues
with the desire to use this quota on other per-cpu rq.

Basically we now check the cfs_b on each return, and decide if all the remaining
time should be returned or to leave min_cfs_rq_runtime on the per-cpu queue
based on how much time is remaining on the cfs_b.  As a result this mostly
gives us the benefits of both worlds.