From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759710Ab3FNB7k (ORCPT ); Thu, 13 Jun 2013 21:59:40 -0400 Received: from szxga01-in.huawei.com ([119.145.14.64]:38400 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759681Ab3FNB7e (ORCPT ); Thu, 13 Jun 2013 21:59:34 -0400 Message-ID: <51BA7831.4040003@huawei.com> Date: Fri, 14 Jun 2013 09:56:01 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Andrew Morton CC: Tejun Heo , Glauber Costa , KAMEZAWA Hiroyuki , Johannes Weiner , LKML , Cgroups , , Michal Hocko , Hugh Dickins Subject: [PATCH v4 9/9] memcg: don't need to free memcg via RCU or workqueue References: <51BA7794.2000305@huawei.com> In-Reply-To: <51BA7794.2000305@huawei.com> Content-Type: text/plain; charset="GB2312" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.135.68.215] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now memcg has the same life cycle with its corresponding cgroup, and a cgroup is freed via RCU and then mem_cgroup_css_free() will be called in a work function, so we can simply call __mem_cgroup_free() in mem_cgroup_css_free(). This actually reverts 59927fb984de1703c67bc640c3e522d8b5276c73 ("memcg: free mem_cgroup by RCU to fix oops"). Cc: Hugh Dickins Signed-off-by: Li Zefan Acked-by: Michal Hocko Acked-by: KAMEZAWA Hiroyuki --- mm/memcontrol.c | 51 +++++---------------------------------------------- 1 file changed, 5 insertions(+), 46 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7b622c3..234f311 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -267,28 +267,10 @@ struct mem_cgroup { /* vmpressure notifications */ struct vmpressure vmpressure; - union { - /* - * the counter to account for mem+swap usage. - */ - struct res_counter memsw; - - /* - * rcu_freeing is used only when freeing struct mem_cgroup, - * so put it into a union to avoid wasting more memory. - * It must be disjoint from the css field. It could be - * in a union with the res field, but res plays a much - * larger part in mem_cgroup life than memsw, and might - * be of interest, even at time of free, when debugging. - * So share rcu_head with the less interesting memsw. - */ - struct rcu_head rcu_freeing; - /* - * We also need some space for a worker in deferred freeing. - * By the time we call it, rcu_freeing is no longer in use. - */ - struct work_struct work_freeing; - }; + /* + * the counter to account for mem+swap usage. + */ + struct res_counter memsw; /* * the counter to account for kernel memory usage. @@ -6182,29 +6164,6 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg) vfree(memcg); } - -/* - * Helpers for freeing a kmalloc()ed/vzalloc()ed mem_cgroup by RCU, - * but in process context. The work_freeing structure is overlaid - * on the rcu_freeing structure, which itself is overlaid on memsw. - */ -static void free_work(struct work_struct *work) -{ - struct mem_cgroup *memcg; - - memcg = container_of(work, struct mem_cgroup, work_freeing); - __mem_cgroup_free(memcg); -} - -static void free_rcu(struct rcu_head *rcu_head) -{ - struct mem_cgroup *memcg; - - memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing); - INIT_WORK(&memcg->work_freeing, free_work); - schedule_work(&memcg->work_freeing); -} - /* * Returns the parent mem_cgroup in memcgroup hierarchy with hierarchy enabled. */ @@ -6355,7 +6314,7 @@ static void mem_cgroup_css_free(struct cgroup *cont) mem_cgroup_sockets_destroy(memcg); - call_rcu(&memcg->rcu_freeing, free_rcu); + __mem_cgroup_free(memcg); } #ifdef CONFIG_MMU -- 1.8.0.2