From: Xishi Qiu <qiuxishi@xxxxxxxxxx> When offline a section, we move all the free pages and pcp into MIGRATE_ISOLATE list first. start_isolate_page_range() set_migratetype_isolate() drain_all_pages(), Here is a problem, it is not sure that pcp will be moved into MIGRATE_ISOLATE list. They may be moved into MIGRATE_MOVABLE list because page_private() maybe 2. So when finish migrating pages, the free pages from pcp may be allocated again, and faild in check_pages_isolated(). drain_all_pages() drain_local_pages() drain_pages() free_pcppages_bulk() __free_one_page(page, zone, 0, page_private(page)); If we add move_freepages_block() after drain_all_pages(), it can not sure that all the pcp will be moved into MIGRATE_ISOLATE list when the system works on high load. The free pages which from pcp may immediately be allocated again. I think the similar bug described in http://marc.info/?t=134250882300003&r=1&w=2 Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx> --- mm/page_alloc.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d0723b2..501f6de 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -673,7 +673,8 @@ static void free_pcppages_bulk(struct zone *zone, int count, /* must delete as __free_one_page list manipulates */ list_del(&page->lru); /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ - __free_one_page(page, zone, 0, page_private(page)); + __free_one_page(page, zone, 0, + get_pageblock_migratetype(page)); trace_mm_page_pcpu_drain(page, 0, page_private(page)); } while (--to_free && --batch_free && !list_empty(list)); } -- 1.7.6.1 . . -- 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>