Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

Pull percpu updates from Tejun Heo:
 "A lot of changes for percpu this time around. percpu inherited the
  same area allocator from the original pre-virtual-address-mapped
  implementation. This was from the time when percpu allocator wasn't
  used all that much and the implementation was focused on simplicity,
  with the unfortunate computational complexity of O(number of areas
  allocated from the chunk) per alloc / free.

  With the increase in percpu usage, we're hitting cases where the lack
  of scalability is hurting. The most prominent one right now is bpf
  perpcu map creation / destruction which may allocate and free a lot of
  entries consecutively and it's likely that the problem will become
  more prominent in the future.

  To address the issue, Dennis replaced the area allocator with hinted
  bitmap allocator which is more consistent. While the new allocator
  does perform a bit worse in some cases, it outperf...