The reclaim_clean_pages_from_list reclaims clean pages before migration so cc.nr_migratepages should be updated. Currently, there is no problem but it can be wrong if we try to use the vaule in future. Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Michal Nazarewicz <mina86@xxxxxxxxxx> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> --- I found this problem during I develop new feature. :( mm/page_alloc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 296bea9..4b7dced 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5669,7 +5669,7 @@ static unsigned long pfn_max_align_up(unsigned long pfn) static int __alloc_contig_migrate_range(unsigned long start, unsigned long end) { /* This function is based on compact_zone() from compaction.c. */ - + unsigned long nr_reclaimed; unsigned long pfn = start; unsigned int tries = 0; int ret = 0; @@ -5705,7 +5705,9 @@ static int __alloc_contig_migrate_range(unsigned long start, unsigned long end) break; } - reclaim_clean_pages_from_list(cc.zone, &cc.migratepages); + nr_reclaimed = reclaim_clean_pages_from_list(cc.zone, + &cc.migratepages); + cc.nr_migratepages -= nr_reclaimed; ret = migrate_pages(&cc.migratepages, alloc_migrate_target, -- 1.7.9.5 -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>