gethugepagesize man page
gethugepagesize — Get the default huge page size
The gethugepagesize() function returns the default huge page size used by libhugetlbfs. This will be either the system default, or a valid value set by the environment variable HUGETLB_DEFAULT_PAGE_SIZE.
If the system does not support any huge page sizes an error is returned.
On success, the default huge page size is returned. On failure, -1 is returned and errno is set appropriately.
The system does not support huge pages.
libhugetlbfs was written by various people on the libhugetlbfs-devel mailing list.
get_hugepage_region(3), get_huge_pages(3), hugetlbfs_find_path(3), hugetlbfs_unlinked_fd(3), libhugetlbfs(7).