In isolate_freepages() check each page in a pageblock instead of checking only first pages of pageblock_nr_pages intervals (suitable_migration_target(page) is called before isolate_freepages_block() so if page is "unsuitable" whole pageblock_nr_pages pages will be ommited from the check). It greatly improves possibility of finding free pages to isolate during compaction_alloc() phase. Cc: Mel Gorman <mgorman@xxxxxxx> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> --- mm/compaction.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index d9ebebe..bc77135 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -65,7 +65,7 @@ static unsigned long isolate_freepages_block(struct zone *zone, /* Get the last PFN we should scan for free pages at */ zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages; - end_pfn = min(blockpfn + pageblock_nr_pages, zone_end_pfn); + end_pfn = min(blockpfn + 1, zone_end_pfn); /* Find the first usable PFN in the block to initialse page cursor */ for (; blockpfn < end_pfn; blockpfn++) { @@ -160,8 +160,7 @@ static void isolate_freepages(struct zone *zone, * pages on cc->migratepages. We stop searching if the migrate * and free page scanners meet or enough free pages are isolated. */ - for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages; - pfn -= pageblock_nr_pages) { + for (; pfn > low_pfn && cc->nr_migratepages > nr_freepages; pfn--) { unsigned long isolated; if (!pfn_valid(pfn)) -- 1.7.9.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>