On Mon, Dec 12, 2011 at 03:23:02PM +0100, Michal Nazarewicz wrote: > >On Fri, Nov 18, 2011 at 05:43:08PM +0100, Marek Szyprowski wrote: > >>From: Michal Nazarewicz <mina86@xxxxxxxxxx> > >>diff --git a/mm/page_alloc.c b/mm/page_alloc.c > >>index 9dd443d..58d1a2e 100644 > >>--- a/mm/page_alloc.c > >>+++ b/mm/page_alloc.c > >>@@ -628,6 +628,18 @@ static void free_pcppages_bulk(struct zone *zone, int count, > >> page = list_entry(list->prev, struct page, lru); > >> /* must delete as __free_one_page list manipulates */ > >> list_del(&page->lru); > >>+ > >>+ /* > >>+ * When page is isolated in set_migratetype_isolate() > >>+ * function it's page_private is not changed since the > >>+ * function has no way of knowing if it can touch it. > >>+ * This means that when a page is on PCP list, it's > >>+ * page_private no longer matches the desired migrate > >>+ * type. > >>+ */ > >>+ if (get_pageblock_migratetype(page) == MIGRATE_ISOLATE) > >>+ set_page_private(page, MIGRATE_ISOLATE); > >>+ > > On Mon, 12 Dec 2011 14:42:35 +0100, Mel Gorman <mel@xxxxxxxxx> wrote: > >How much of a problem is this in practice? > > IIRC, this lead to allocation being made from area marked as isolated > or some such. > And I believe that nothing prevents that from happening. I was just wondering how common it was in practice. Draining the per-cpu lists should work as a substitute either way. -- Mel Gorman SUSE Labs -- 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>