HSTATE_ATTR_RO   2722 mm/hugetlb.c   HSTATE_ATTR_RO(free_hugepages);
HSTATE_ATTR_RO   2730 mm/hugetlb.c   HSTATE_ATTR_RO(resv_hugepages);
HSTATE_ATTR_RO   2747 mm/hugetlb.c   HSTATE_ATTR_RO(surplus_hugepages);