hugetlb_unreserve_pages
if (unlikely(hugetlb_unreserve_pages(inode, index,
(void)hugetlb_unreserve_pages(inode,
long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
hugetlb_unreserve_pages(inode, idx, idx + 1, 0);