Pull percpu updates from Tejun Heo:
 "These are the percpu changes for the v4.13-rc1 merge window. There are
  a couple visibility related changes - tracepoints and allocator stats
  through debugfs, along with __ro_after_init markings and a cosmetic
  rename in percpu_counter.

  Please note that the simple O(#elements_in_the_chunk) area allocator
  used by percpu allocator is again showing scalability issues,
  primarily with bpf allocating and freeing large number of counters.
  Dennis is working on the replacement allocator and the percpu
  allocator will be seeing increased churns in the coming cycles"

* 'for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: fix static checker warnings in pcpu_destroy_chunk
  percpu: fix early calls for spinlock in pcpu_stats
  percpu: resolve err may not be initialized in pcpu_alloc
  percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch
  percpu: add tracepoint support for percpu memory
  percpu: expose statistics about percpu memory via debugfs
  percpu: migrate percpu data structures to internal header
  percpu: add missing lockdep_assert_held to func pcpu_free_area
  mark most percpu globals as __ro_after_init