Pull percpu fixes from Tejun Heo:
"While adding GFP_ATOMIC support to the percpu allocator, the
synchronization for the fast-path which doesn't require external
allocations was separated into pcpu_lock.
Unfortunately, it incorrectly decoupled async paths and percpu
chunks could get destroyed while still being operated on. This
contains two patches to fix the bug"
* 'for-4.7-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: fix synchronization between synchronous map extension and chunk destruction
percpu: fix synchronization between chunk->map_extend_work and chunk destruction