linux-master/mm/migrate.c

70 	 * raise its refcount preventing __free_pages() from doing its job
94 	 * As movable pages are not isolated from LRU lists, concurrent
141  * from where they were once taken off for compaction/migration.
144  * built from lru, balloon, hugetlbfs page. See isolate_migratepages_range()
304  * When we return from this function the fault will be retried.
337  * the pte or the ptl from being freed.
418 		/* No turning back from here */
438 	 * no turning back from here.
469 	 * Drop cache reference from old page by unfreezing
814  * @src: The folio to migrate from.
836  * @src: The folio to migrate from.
1124 		/* Folio was freed from under us. So we are done. */
1201 	 * getting a hold on an anon_vma from outside one of its mms.
1210 	 * Block others from accessing the new page when we get around to
1301 	 * isolated from the unevictable LRU: but this case is the easiest.
1380 		/* page was freed from under us. So we are done. */
1523 static int migrate_hugetlbs(struct list_head *from, new_folio_t get_new_folio,
1540 		list_for_each_entry_safe(folio, folio2, from, lru) {
1569 			 *	-EAGAIN: stay on the from list
1570 			 *	-ENOMEM: stay on the from list
1592 				 * removed from migration folio list and not
1613  * migrate_pages_batch() first unmaps folios in the from list as many as
1619  * length of the from list must be <= 1.
1621 static int migrate_pages_batch(struct list_head *from,
1641 			!list_empty(from) && !list_is_singular(from));
1648 		list_for_each_entry_safe(folio, folio2, from, lru) {
1658 			 * Only check it without removing it from the list.
1709 			 *	-EAGAIN: stay on the from list
1710 			 *	-ENOMEM: stay on the from list
1770 				 * removed from migration folio list and not
1855 static int migrate_pages_sync(struct list_head *from, new_folio_t get_new_folio,
1867 	rc = migrate_pages_batch(from, get_new_folio, put_new_folio, private, MIGRATE_ASYNC,
1891 	list_splice_tail_init(&folios, from);
1892 	while (!list_empty(from)) {
1893 		list_move(from->next, &folios);
1910  * @from:		The list of folios to be migrated.
1932 int migrate_pages(struct list_head *from, new_folio_t get_new_folio,
1948 	rc_gather = migrate_hugetlbs(from, get_new_folio, put_new_folio, private,
1955 	list_for_each_entry_safe(folio, folio2, from, lru) {
1967 		list_cut_before(&folios, from, &folio2->lru);
1969 		list_splice_init(from, &folios);
1997 	if (!list_empty(from))
2004 	list_splice(&ret_folios, from);
2010 	if (list_empty(from))
2098  * Resolves the given address to a struct page, isolates it from the LRU and
2162 	 * Either remove the duplicate refcount from folio_isolate_lru()