Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935045Ab3DHGiN (ORCPT ); Mon, 8 Apr 2013 02:38:13 -0400 Received: from szxga01-in.huawei.com ([119.145.14.64]:30231 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934863Ab3DHGiL (ORCPT ); Mon, 8 Apr 2013 02:38:11 -0400 Message-ID: <51626570.8000400@huawei.com> Date: Mon, 8 Apr 2013 14:36:32 +0800 From: Li Zefan User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:17.0) Gecko/20130328 Thunderbird/17.0.5 MIME-Version: 1.0 To: Andrew Morton CC: Tejun Heo , Glauber Costa , KAMEZAWA Hiroyuki , Johannes Weiner , LKML , Cgroups , , Hugh Dickins Subject: [PATCH 12/12] memcg: don't need to free memcg via RCU or workqueue References: <5162648B.9070802@huawei.com> In-Reply-To: <5162648B.9070802@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 Content-Length: 2926 Lines: 97 Now memcg has the same life cycle with its corresponding cgroup, and a cgroup is freed via RCU and then mem_cgroup_css_free() is 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 --- mm/memcontrol.c | 51 +++++---------------------------------------------- 1 file changed, 5 insertions(+), 46 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a6d44bc..5aa6e91 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -261,28 +261,10 @@ struct mem_cgroup { */ struct res_counter res; - 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. @@ -6097,29 +6079,6 @@ 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. */ @@ -6269,7 +6228,7 @@ 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 -- 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/