Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756195AbZCXIDK (ORCPT ); Tue, 24 Mar 2009 04:03:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754461AbZCXICs (ORCPT ); Tue, 24 Mar 2009 04:02:48 -0400 Received: from TYO202.gate.nec.co.jp ([202.32.8.206]:57612 "EHLO tyo202.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754434AbZCXICq (ORCPT ); Tue, 24 Mar 2009 04:02:46 -0400 Date: Tue, 24 Mar 2009 16:57:43 +0900 From: Daisuke Nishimura To: Andrew Morton Cc: linux-kernel@vger.kernel.org, KAMEZAWA Hiroyuki , Balbir Singh , Daisuke Nishimura Subject: [BUGFIX][PATCH(resend) mmotm] memcg: try_get_mem_cgroup_from_swapcache fix (Re: 2.6.30 -mm merge plans) Message-Id: <20090324165743.bfaefecb.nishimura@mxp.nes.nec.co.jp> In-Reply-To: <20090323224615.cd29edfd.akpm@linux-foundation.org> References: <20090323224615.cd29edfd.akpm@linux-foundation.org> 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: 2366 Lines: 69 > memcg-use-css-id.patch > memcg-hierarchical-stat.patch > memcg-fix-shrinking-memory-to-return-ebusy-by-fixing-retry-algorithm.patch > memcg-fix-oom-killer-under-memcg.patch > memcg-fix-oom-killer-under-memcg-fix2.patch > memcg-fix-oom-killer-under-memcg-fix.patch > memcg-show-memcg-information-during-oom.patch > memcg-show-memcg-information-during-oom-fix2.patch > memcg-show-memcg-information-during-oom-fix.patch > memcg-show-memcg-information-during-oom-fix-fix.patch > memcg-show-memcg-information-during-oom-fix-fix-checkpatch-fixes.patch > memcg-remove-mem_cgroup_calc_mapped_ratio-take2.patch > memcg-remove-mem_cgroup_reclaim_imbalance-remnants.patch > memcg-charge-swapcache-to-proper-memcg.patch > cgroups-use-css-id-in-swap-cgroup-for-saving-memory-v5.patch > memcg-remove-redundant-message-at-swapon.patch > > Merge > This patch is fix for cgroups-use-css-id-in-swap-cgroup-for-saving-memory-v5.patch. I think it would be better to fold them. === From: Daisuke Nishimura css_tryget can be called twice in !PageCgroupUsed case. Signed-off-by: Daisuke Nishimura Acked-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 10 ++++------ 1 files changed, 4 insertions(+), 6 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5de6be9..55dea59 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1027,9 +1027,11 @@ static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page) /* * Used bit of swapcache is solid under page lock. */ - if (PageCgroupUsed(pc)) + if (PageCgroupUsed(pc)) { mem = pc->mem_cgroup; - else { + if (mem && !css_tryget(&mem->css)) + mem = NULL; + } else { ent.val = page_private(page); id = lookup_swap_cgroup(ent); rcu_read_lock(); @@ -1038,10 +1040,6 @@ static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page) mem = NULL; rcu_read_unlock(); } - if (!mem) - return NULL; - if (!css_tryget(&mem->css)) - return NULL; return mem; } -- 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/