On Tue, May 31, 2011 at 04:14:02PM +0200, Andrea Arcangeli wrote: > On Tue, May 31, 2011 at 10:33:40PM +0900, Minchan Kim wrote: > > I checked them before sending patch but I got failed to find strange things. :( > > My review also doesn't show other bugs in migrate_pages callers like > that one. > > > Now I am checking the page's SwapBacked flag can be changed > > between before and after of migrate_pages so accounting of NR_ISOLATED_XX can > > make mistake. I am approaching the failure, too. Hmm. > > When I checked that, I noticed the ClearPageSwapBacked in swapcache if > radix insertion fails, but that happens before adding the page in the > LRU so it shouldn't have a chance to be isolated. True. > > So far I only noticed an unsafe page_count in > vmscan.c:isolate_lru_pages but that should at worst result in a > invalid pointer dereference as random result from that page_count is > not going to hurt and I think it's only a theoretical issue. Yes. You find a new BUG. It seems to be related to this problem but it should be solved although it's very rare case. -- Kind regards Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx 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>