Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760910AbZANI6U (ORCPT ); Wed, 14 Jan 2009 03:58:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755736AbZANI6K (ORCPT ); Wed, 14 Jan 2009 03:58:10 -0500 Received: from TYO201.gate.nec.co.jp ([202.32.8.193]:36900 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755709AbZANI6I (ORCPT ); Wed, 14 Jan 2009 03:58:08 -0500 Date: Wed, 14 Jan 2009 17:51:21 +0900 From: Daisuke Nishimura To: LKML , linux-mm Cc: Andrew Morton , Balbir Singh , KAMEZAWA Hiroyuki , Pavel Emelyanov , Li Zefan , Paul Menage , nishimura@mxp.nes.nec.co.jp Subject: [RFC][PATCH 5/4] memcg: don't call res_counter_uncharge when obsolete Message-Id: <20090114175121.275ecd59.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20090113184533.6ffd2af9.nishimura@mxp.nes.nec.co.jp> References: <20090113184533.6ffd2af9.nishimura@mxp.nes.nec.co.jp> Organization: NEC Soft, Ltd. X-Mailer: Sylpheed 2.4.8 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2031 Lines: 58 This is a new one. Please review. === From: Daisuke Nishimura mem_cgroup_get ensures that the memcg that has been got can be accessed even after the directory has been removed, but it doesn't ensure that parents of it can be accessed: parents might have been freed already by rmdir. This causes a bug in case of use_hierarchy==1, because res_counter_uncharge climb up the tree. Check if the memcg is obsolete, and don't call res_counter_uncharge when obsole. Signed-off-by: Daisuke Nishimura --- mm/memcontrol.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index fb62b43..4ee95a8 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1182,7 +1182,8 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm, /* avoid double counting */ mem = swap_cgroup_record(ent, NULL); if (mem) { - res_counter_uncharge(&mem->memsw, PAGE_SIZE); + if (!mem_cgroup_is_obsolete(mem)) + res_counter_uncharge(&mem->memsw, PAGE_SIZE); mem_cgroup_put(mem); } } @@ -1252,7 +1253,8 @@ void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr) struct mem_cgroup *memcg; memcg = swap_cgroup_record(ent, NULL); if (memcg) { - res_counter_uncharge(&memcg->memsw, PAGE_SIZE); + if (!mem_cgroup_is_obsolete(memcg)) + res_counter_uncharge(&memcg->memsw, PAGE_SIZE); mem_cgroup_put(memcg); } @@ -1397,7 +1399,8 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent) memcg = swap_cgroup_record(ent, NULL); if (memcg) { - res_counter_uncharge(&memcg->memsw, PAGE_SIZE); + if (!mem_cgroup_is_obsolete(memcg)) + res_counter_uncharge(&memcg->memsw, PAGE_SIZE); mem_cgroup_put(memcg); } } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/