On Thu, Jan 6, 2011 at 10:09 AM, Daisuke Nishimura <nishimura@xxxxxxxxxxxxxxxxx> wrote: > On Wed, 5 Jan 2011 12:58:40 +0100 > Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > >> On Wed, Jan 05, 2011 at 01:00:20PM +0900, Daisuke Nishimura wrote: >> > In current implimentation, mem_cgroup_end_migration() decides whether the page >> > migration has succeeded or not by checking "oldpage->mapping". >> > >> > But if we are tring to migrate a shmem swapcache, the page->mapping of it is >> > NULL from the begining, so the check would be invalid. >> > As a result, mem_cgroup_end_migration() assumes the migration has succeeded >> > even if it's not, so "newpage" would be freed while it's not uncharged