18  * sentinel head node, "prev" links not maintained.
25 	struct list_head head, *tail = &head;  in merge()  local
39 	return head.next;  in merge()
52 				struct list_head *head,  in merge_and_restore_back_links()  argument
55 	struct list_head *tail = head;  in merge_and_restore_back_links()
85 	tail->next = head;  in merge_and_restore_back_links()
86 	head->prev = tail;  in merge_and_restore_back_links()
92  * @head: the list to sort
103 void list_sort(void *priv, struct list_head *head,  in list_sort()  argument
113 	if (list_empty(head))  in list_sort()
118 	head->prev->next = NULL;  in list_sort()
119 	list = head->next;  in list_sort()
146 	merge_and_restore_back_links(priv, cmp, head, part[max_lev], list);  in list_sort()
158 #define TEST_LIST_LEN (512+128+2) /* not including head */
219 	LIST_HEAD(head);  in list_sort_test()
243 		list_add_tail(&el->list, &head);  in list_sort_test()
246 	list_sort(NULL, &head, cmp);  in list_sort_test()
248 	for (cur = head.next; cur->next != &head; cur = cur->next) {  in list_sort_test()
290 	list_for_each_safe(cur, tmp, &head) {  in list_sort_test()