From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756838AbYLJXqa (ORCPT ); Wed, 10 Dec 2008 18:46:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755911AbYLJXpo (ORCPT ); Wed, 10 Dec 2008 18:45:44 -0500 Received: from smtp-out.google.com ([216.239.45.13]:21362 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755829AbYLJXpn (ORCPT ); Wed, 10 Dec 2008 18:45:43 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=message-id:references:user-agent:date:from:to:cc:subject:content-disposition; b=uSf0Yc99an6oQ2N6wil1t5iV8Vj/otqmrod9G5ASZLNAFWh1JWXZBjAyb4PlOIn25 fAG6TqTW9qTKgdTUe01aw== Message-Id: <20081210234432.236302000@menage.corp.google.com> References: <20081210233654.563182000@menage.corp.google.com> User-Agent: quilt/0.45-1 Date: Wed, 10 Dec 2008 15:36:56 -0800 From: menage@google.com To: kamezawa.hiroyu@jp.fujitsu.com, balbir@linux.vnet.ibm.com, containers@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org Subject: [RFC][PATCH 2/3] CGroups: Use hierarchy_mutex in memory controller Content-Disposition: inline; filename=mm-destroy-fix.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch updates the memory controller to use its hierarchy_mutex rather than calling cgroup_lock() to protected against cgroup_mkdir()/cgroup_rmdir() from occurring in its hierarchy. Signed-off-by: Paul Menage --- mm/memcontrol.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) Index: hierarchy_lock-mmotm-2008-12-09/mm/memcontrol.c =================================================================== --- hierarchy_lock-mmotm-2008-12-09.orig/mm/memcontrol.c +++ hierarchy_lock-mmotm-2008-12-09/mm/memcontrol.c @@ -154,7 +154,7 @@ struct mem_cgroup { /* * While reclaiming in a hiearchy, we cache the last child we - * reclaimed from. Protected by cgroup_lock() + * reclaimed from. Protected by hierarchy_mutex */ struct mem_cgroup *last_scanned_child; /* @@ -529,7 +529,7 @@ unsigned long mem_cgroup_isolate_pages(u /* * This routine finds the DFS walk successor. This routine should be - * called with cgroup_mutex held + * called with hierarchy_mutex held */ static struct mem_cgroup * mem_cgroup_get_next_node(struct mem_cgroup *curr, struct mem_cgroup *root_mem) @@ -598,7 +598,7 @@ mem_cgroup_get_first_node(struct mem_cgr /* * Scan all children under the mem_cgroup mem */ - cgroup_lock(); + mutex_lock(&mem_cgroup_subsys.hierarchy_mutex); if (list_empty(&root_mem->css.cgroup->children)) { ret = root_mem; goto done; @@ -619,7 +619,7 @@ mem_cgroup_get_first_node(struct mem_cgr done: root_mem->last_scanned_child = ret; - cgroup_unlock(); + mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); return ret; } @@ -683,18 +683,16 @@ static int mem_cgroup_hierarchical_recla while (next_mem != root_mem) { if (next_mem->obsolete) { mem_cgroup_put(next_mem); - cgroup_lock(); next_mem = mem_cgroup_get_first_node(root_mem); - cgroup_unlock(); continue; } ret = try_to_free_mem_cgroup_pages(next_mem, gfp_mask, noswap, get_swappiness(next_mem)); if (mem_cgroup_check_under_limit(root_mem)) return 0; - cgroup_lock(); + mutex_lock(&mem_cgroup_subsys.hierarchy_mutex); next_mem = mem_cgroup_get_next_node(next_mem, root_mem); - cgroup_unlock(); + mutex_unlock(&mem_cgroup_subsys.hierarchy_mutex); } return ret; } --