On 07/22/2015 12:43 AM, David Rientjes wrote: > On Tue, 21 Jul 2015, Vlastimil Babka wrote: > > > You may want to consider stating your assumptions explicitly in the code, > perhaps with VM_BUG_ON(), such as in free_pcppages_bulk() to ensure things > like get_freepage_migratetype(page) != MIGRATE_ISOLATE. Hm, OK here's a fixup. I've pondered others but nothing made sense unless I would have to devise really twisted ways in which somebody broke the code in the future, and that's not worth BUG_ON(). But the checking made me realize that one more set_freepage_migratetype() can be removed in the other patch, so I will resend it. ------8<------ From: Vlastimil Babka <vbabka@xxxxxxx> Date: Wed, 22 Jul 2015 14:16:52 +0200 Subject: [PATCH 2/3] fixup! mm, page_isolation: remove bogus tests for isolated pages --- mm/page_alloc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 41dc650..c61fef8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -789,7 +789,11 @@ 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); + mt = get_freepage_migratetype(page); + /* MIGRATE_ISOLATE page should not go to pcplists */ + VM_BUG_ON_PAGE(is_migrate_isolate(mt), page); + /* Pageblock could have been isolated meanwhile */ if (unlikely(has_isolate_pageblock(zone))) mt = get_pageblock_migratetype(page); -- 2.4.5 -- 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>