From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id EBA6B6B00A1 for ; Mon, 19 Jan 2009 04:34:47 -0500 (EST) Received: from mt1.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n0J9Yjg0010001 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 19 Jan 2009 18:34:45 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 5E96845DE4F for ; Mon, 19 Jan 2009 18:34:45 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 40E8C45DE4E for ; Mon, 19 Jan 2009 18:34:45 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 2F3161DB803A for ; Mon, 19 Jan 2009 18:34:45 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id DCCE51DB8037 for ; Mon, 19 Jan 2009 18:34:44 +0900 (JST) Date: Mon, 19 Jan 2009 18:33:41 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [memcg BUG] NULL pointer dereference wheng rmdir Message-Id: <20090119183341.9418c6de.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <49744499.2040101@cn.fujitsu.com> References: <49744499.2040101@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Li Zefan Cc: Balbir Singh , Daisuke Nishimura , "linux-mm@kvack.org" List-ID: On Mon, 19 Jan 2009 17:15:05 +0800 Li Zefan wrote: > note: rmdir[11520] exited with preempt_count 1 > =========================================================================== > > > And I've confirmed it's because (zone == NULL) in mem_cgroup_force_empty_list(): > > Hmm, curious. it will be == for_each_node_state(nid, N_POSSIBLE) for (zid = 0; zid < MAX_NR_ZONES; zid++) zone = &NODE_DATA(nid)->node_zones[zid]; == And, from this message, Unable to handle kernel NULL pointer dereference (address 0000000000002680) NODE_DATA(nid) seems to be NULL. Hmm...could you try this ? Thank you for nice test, very helpful. -Kame == From: KAMEZAWA Hiroyuki N_POSSIBLE doesn't means there is memory...and force_empty can visit invalud node which have no pgdat. To visit all valid nodes, N_HIGH_MEMRY should be used. Reporetd-by: Li Zefan Signed-off-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: mmotm-2.6.29-Jan16/mm/memcontrol.c =================================================================== --- mmotm-2.6.29-Jan16.orig/mm/memcontrol.c +++ mmotm-2.6.29-Jan16/mm/memcontrol.c @@ -1724,7 +1724,7 @@ move_account: /* This is for making all *used* pages to be on LRU. */ lru_add_drain_all(); ret = 0; - for_each_node_state(node, N_POSSIBLE) { + for_each_node_state(node, N_HIGH_MEMORY) { for (zid = 0; !ret && zid < MAX_NR_ZONES; zid++) { enum lru_list l; for_each_lru(l) { -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org