Merge branch 'akpm' (patches from Andrew)

Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:
 "Subsystems affected by this patch series: mm (memcg, migration,
  pagemap, gup, madvise, vmalloc), ia64, and misc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (31 commits)
  mm: remove duplicate include statement in mmu.c
  mm: remove the filename in the top of file comment in vmalloc.c
  mm: cleanup the gfp_mask handling in __vmalloc_area_node
  mm: remove alloc_vm_area
  x86/xen: open code alloc_vm_area in arch_gnttab_valloc
  xen/xenbus: use apply_to_page_range directly in xenbus_map_ring_pv
  drm/i915: use vmap in i915_gem_object_map
  drm/i915: stop using kmap in i915_gem_object_map
  drm/i915: use vmap in shmem_pin_map
  zsmalloc: switch from alloc_vm_area to get_vm_area
  mm: allow a NULL fn callback in apply_to_page_range
  mm: add a vmap_pfn function
  mm: add a VM_MAP_PUT_PAGES flag for vmap
  mm: update the documentation for vfree
  mm/madvise: introduce process_madvise() syscall: an external memory hinting API
  pid: move pidfd_get_pid() to pid.c
  mm/madvise: pass mm to do_madvise
  selftests/vm: 10x speedup for hmm-tests
  binfmt_elf: take the mmap lock around find_extend_vma()
  mm/gup_benchmark: take the mmap lock around GUP
  ...