Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "The remainder of the main mm/ queue.

  143 patches.

  Subsystems affected by this patch series (all mm): pagecache, hugetlb,
  userfaultfd, vmscan, compaction, migration, cma, ksm, vmstat, mmap,
  kconfig, util, memory-hotplug, zswap, zsmalloc, highmem, cleanups, and
  kfence"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (143 commits)
  kfence: use power-efficient work queue to run delayed work
  kfence: maximize allocation wait timeout duration
  kfence: await for allocation using wait_event
  kfence: zero guard page after out-of-bounds access
  mm/process_vm_access.c: remove duplicate include
  mm/mempool: minor coding style tweaks
  mm/highmem.c: fix coding style issue
  btrfs: use memzero_page() instead of open coded kmap pattern
  iov_iter: lift memzero_page() to highmem.h
  mm/zsmalloc: use BUG_ON instead of if condition followed by BUG.
  mm/zswap.c: switch from strlcpy to strscpy
  arm64/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
  x86/Kconfig: introduce ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
  mm,memory_hotplug: add kernel boot option to enable memmap_on_memory
  acpi,memhotplug: enable MHP_MEMMAP_ON_MEMORY when supported
  mm,memory_hotplug: allocate memmap from the added memory range
  mm,memory_hotplug: factor out adjusting present pages into adjust_present_page_count()
  mm,memory_hotplug: relax fully spanned sections check
  drivers/base/memory: introduce memory_block_{online,offline}
  mm/memory_hotplug: remove broken locking of zone PCP structures during hot remove
  ...

diff --cc Documentation/admin-guide/kernel-parameters.txt
Simple merge

diff --cc arch/powerpc/Kconfig
index 1e6230b,d433304..cb2d44e
--- 1/arch/powerpc/Kconfig
--- 2/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@@ -118,8 -118,9 +118,10 @@@ config PP
        # Please keep this list sorted alphabetically.
        #
        select ARCH_32BIT_OFF_T if PPC32
+       select ARCH_ENABLE_MEMORY_HOTPLUG
+       select ARCH_ENABLE_MEMORY_HOTREMOVE
        select ARCH_HAS_DEBUG_VIRTUAL
 +      select ARCH_HAS_DEBUG_VM_PGTABLE
        select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_HAS_ELF_RANDOMIZE
        select ARCH_HAS_FORTIFY_SOURCE

diff --cc arch/powerpc/platforms/Kconfig.cputype
Simple merge

diff --cc arch/riscv/Kconfig
Simple merge

diff --cc fs/buffer.c
Simple merge

diff --cc init/Kconfig
Simple merge