From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx161.postini.com [74.125.245.161]) by kanga.kvack.org (Postfix) with SMTP id 5D1DB6B005D for ; Tue, 4 Dec 2012 03:36:23 -0500 (EST) Message-ID: <50BDB601.4090205@oracle.com> Date: Tue, 04 Dec 2012 16:36:17 +0800 From: Jeff Liu MIME-Version: 1.0 Subject: [RFC PATCH 3/3] memcg: allocate pages for swap cgroup until the first child memcg is alive Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: cgroups@vger.kernel.org, Glauber Costa - Call swap_cgroup_init() when the first child memcg was created. - Free pages from swap cgroup once the latest child memcg was removed. - Teach swap_cgroup_record()/swap_cgroup_cmpxchg()/swap_cgroup_lookup_id() to aware of the new static variable. i.e, swap_cgroup_initialized, so that they would not perform further jobs if swap cgroup is not active. Signed-off-by: Jie Liu CC: Glauber Costa CC: Michal Hocko CC: Kamezawa Hiroyuki CC: Johannes Weiner CC: Mel Gorman CC: Andrew Morton --- mm/memcontrol.c | 3 +++ mm/page_cgroup.c | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index dd39ba0..1f14375 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4982,6 +4982,8 @@ mem_cgroup_create(struct cgroup *cont) } hotcpu_notifier(memcg_cpu_hotplug_callback, 0); } else { + if (swap_cgroup_init()) + goto free_out; parent = mem_cgroup_from_cont(cont->parent); memcg->use_hierarchy = parent->use_hierarchy; memcg->oom_kill_disable = parent->oom_kill_disable; @@ -5046,6 +5048,7 @@ static void mem_cgroup_destroy(struct cgroup *cont) struct mem_cgroup *memcg = mem_cgroup_from_cont(cont); kmem_cgroup_destroy(memcg); + swap_cgroup_destroy(); mem_cgroup_put(memcg); } diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c index f1b257b..63c6789 100644 --- a/mm/page_cgroup.c +++ b/mm/page_cgroup.c @@ -429,6 +429,9 @@ unsigned short swap_cgroup_cmpxchg(swp_entry_t ent, unsigned long flags; unsigned short retval; + if (!atomic_read(&swap_cgroup_initialized)) + return 0; + sc = lookup_swap_cgroup(ent, &ctrl); spin_lock_irqsave(&ctrl->lock, flags); @@ -456,6 +459,9 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) unsigned short old; unsigned long flags; + if (!atomic_read(&swap_cgroup_initialized)) + return 0; + sc = lookup_swap_cgroup(ent, &ctrl); spin_lock_irqsave(&ctrl->lock, flags); @@ -474,6 +480,9 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id) */ unsigned short lookup_swap_cgroup_id(swp_entry_t ent) { + if (!atomic_read(&swap_cgroup_initialized)) + return 0; + return lookup_swap_cgroup(ent, NULL)->id; } -- 1.7.9.5 -- 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