hugetlb_vmemmap_size
vmemmap_end = vmemmap_start + hugetlb_vmemmap_size(h);
vmemmap_end = vmemmap_start + hugetlb_vmemmap_size(h);
vmemmap_end = vmemmap_start + hugetlb_vmemmap_size(h);
int size = hugetlb_vmemmap_size(h) - HUGETLB_VMEMMAP_RESERVE_SIZE;