linux/mm/compaction.c

823  * @low_pfn:	The first PFN to isolate
828  * [low_pfn, end_pfn). The range is expected to be within same pageblock.
837 isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
848 	unsigned long start_pfn = low_pfn;
854 	cc->migrate_pfn = low_pfn;
880 		next_skip_pfn = block_end_pfn(low_pfn, cc->order);
884 	for (; low_pfn < end_pfn; low_pfn++) {
887 		if (skip_on_failure && low_pfn >= next_skip_pfn) {
901 			 * next_skip_pfn by 1 << order, as low_pfn might have
906 			next_skip_pfn = block_end_pfn(low_pfn, cc->order);
914 		if (!(low_pfn % COMPACT_CLUSTER_MAX)) {
932 		page = pfn_to_page(low_pfn);
940 		if (!valid_page && (pageblock_aligned(low_pfn) ||
941 				    low_pfn == cc->zone->zone_start_pfn)) {
943 				low_pfn = end_pfn;
960 					low_pfn += (1UL << order) - 1;
982 				low_pfn += (1UL << order) - 1;
992 				low_pfn += folio_nr_pages(folio) - 1;
1016 			 * valid order range to prevent low_pfn overflow.
1019 				low_pfn += (1UL << freepage_order) - 1;
1039 					low_pfn += (1UL << order) - 1;
1177 					low_pfn = end_pfn;
1188 				low_pfn += folio_nr_pages(folio) - 1;
1197 			low_pfn += folio_nr_pages(folio) - 1;
1220 			++low_pfn;
1253 		if (low_pfn < next_skip_pfn) {
1254 			low_pfn = next_skip_pfn - 1;
1270 	if (unlikely(low_pfn > end_pfn))
1271 		low_pfn = end_pfn;
1291 	if (low_pfn == end_pfn && (!nr_isolated || cc->finish_pageblock)) {
1294 		update_cached_migrate(cc, low_pfn);
1297 	trace_mm_compaction_isolate_migratepages(start_pfn, low_pfn,
1305 	cc->migrate_pfn = low_pfn;
1508 	unsigned long low_pfn, min_pfn, highest = 0;
1533 	low_pfn = pageblock_start_pfn(cc->free_pfn - (distance >> 2));
1536 	if (WARN_ON_ONCE(min_pfn > low_pfn))
1537 		low_pfn = min_pfn;
1571 			if (pfn >= low_pfn) {
1669 	low_pfn = page_to_pfn(page);
1670 	fast_isolate_around(cc, low_pfn);
1684 	unsigned long low_pfn;	     /* lowest pfn scanner is able to scan */
1707 	low_pfn = pageblock_end_pfn(cc->migrate_pfn);
1715 	for (; block_start_pfn >= low_pfn;
1735 				block_start_pfn = max(next_pfn, low_pfn);
1788 	 * and the loop terminated due to isolate_start_pfn < low_pfn
2049 	unsigned long low_pfn;
2061 	low_pfn = fast_find_migrateblock(cc);
2062 	block_start_pfn = pageblock_start_pfn(low_pfn);
2071 	fast_find_block = low_pfn != cc->migrate_pfn && !cc->fast_search_fail;
2074 	block_end_pfn = pageblock_end_pfn(low_pfn);
2082 			cc->migrate_pfn = low_pfn = block_end_pfn,
2091 		if (!(low_pfn % (COMPACT_CLUSTER_MAX * pageblock_nr_pages)))
2112 		if ((pageblock_aligned(low_pfn) ||
2113 		     low_pfn == cc->zone->zone_start_pfn) &&
2131 		if (isolate_migratepages_block(cc, low_pfn, block_end_pfn,