This series amis to add hugetlb_free_vmemmap sysctl to enable the feature
of freeing vmemmap pages of HugeTLB pages.

v2:
  - Fix compilation when !CONFIG_MHP_MEMMAP_ON_MEMORY reported by kernel
    test robot <lkp@intel.com>.
  - Move sysctl code from kernel/sysctl.c to mm/hugetlb_vmemmap.c.

Muchun Song (3):
  mm: hugetlb: disable freeing vmemmap pages when struct page crosses
    page boundaries
  sysctl: allow to set extra1 to SYSCTL_ONE
  mm: hugetlb: add hugetlb_free_vmemmap sysctl

 Documentation/admin-guide/sysctl/vm.rst | 13 ++++++++++
 include/linux/memory_hotplug.h          |  9 +++++++
 kernel/sysctl.c                         |  2 +-
 mm/hugetlb_vmemmap.c                    | 43 ++++++++++++++++++++++++++++++++-
 mm/hugetlb_vmemmap.h                    |  4 ++-
 mm/memory_hotplug.c                     |  5 ++++
 6 files changed, 73 insertions(+), 3 deletions(-)

-- 
2.11.0