static void add_hugetlb_page(struct hstate *h, struct page *page,
			     bool adjust_surplus)
{
	int zeroed;
	int nid = page_to_nid(page);

	VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page);

	lockdep_assert_held(&hugetlb_lock);

	INIT_LIST_HEAD(&page->lru);
	h->nr_huge_pages++;
	h->nr_huge_pages_node[nid]++;

	if (adjust_surplus) {
		h->surplus_huge_pages++;
		h->surplus_huge_pages_node[nid]++;
	}

	set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
	set_page_private(page, 0);
	SetHPageVmemmapOptimized(page);

	/*
	 * This page is about to be managed by the hugetlb allocator and
	 * should have no users.  Drop our reference, and check for others
	 * just in case.
	 */
	zeroed = put_page_testzero(page);
	if (!zeroed)
		/*
		 * It is VERY unlikely soneone else has taken a ref on
		 * the page.  In this case, we simply return as the
		 * hugetlb destructor (free_huge_page) will be called
		 * when this other ref is dropped.
		 */
		return;

	arch_clear_hugepage_flags(page);
	enqueue_huge_page(h, page);
}
Unknown