On Fri, 17 Dec 2010, KAMEZAWA Hiroyuki wrote: > No. memory cgroup expects all pages should be found on LRU. But, IIUC, > pages on this radix-tree will not be on LRU. So, memory cgroup can't find > it at destroying cgroup and can't reduce "usage" of resource to be 0. > This makes rmdir() returns -EBUSY. Oh, right. Yes, the page will be on the LRU (it needs to be, otherwise the VM coulnd't reclaim it). After the add_to_page_cache_locked is this: if (!(buf->flags & PIPE_BUF_FLAG_LRU)) lru_cache_add_file(newpage); It will add the page to the LRU, unless it's already on it. Thanks, Miklos -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>