Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935008Ab3DHGhm (ORCPT ); Mon, 8 Apr 2013 02:37:42 -0400 Received: from szxga01-in.huawei.com ([119.145.14.64]:29913 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761657Ab3DHGhl (ORCPT ); Mon, 8 Apr 2013 02:37:41 -0400 Message-ID: <51626584.7050405@huawei.com> Date: Mon, 8 Apr 2013 14:36:52 +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 , Subject: [PATCH 13/12] memcg: don't need memcg->memcg_name 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: 4087 Lines: 121 Now memcg has the same life cycle as its corresponding cgroup, we don't have to save the cgroup path name in memcg->memcg_name. Signed-off-by: Li Zefan --- mm/memcontrol.c | 65 +++++++++++++++++++++------------------------------------ 1 file changed, 24 insertions(+), 41 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index aeab1d3..06e995e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -306,20 +306,12 @@ struct mem_cgroup { struct list_head dead; }; - union { - /* - * Should we move charges of a task when a task is moved into - * this mem_cgroup ? And what type of charges should we move ? - */ - unsigned long move_charge_at_immigrate; + /* + * Should we move charges of a task when a task is moved into + * this mem_cgroup ? And what type of charges should we move ? + */ + unsigned long move_charge_at_immigrate; - /* - * We are no longer concerned about moving charges after memcg - * is dead. So we will fill this up with its name, to aid - * debugging. - */ - char *memcg_name; - }; /* * set > 0 if pages under this cgroup are moving to other cgroup. */ @@ -381,36 +373,10 @@ static inline void memcg_dangling_free(struct mem_cgroup *memcg) mutex_lock(&dangling_memcgs_mutex); list_del(&memcg->dead); mutex_unlock(&dangling_memcgs_mutex); - free_pages((unsigned long)memcg->memcg_name, 0); } static inline void memcg_dangling_add(struct mem_cgroup *memcg) { - /* - * cgroup.c will do page-sized allocations most of the time, - * so we'll just follow the pattern. Also, __get_free_pages - * is a better interface than kmalloc for us here, because - * we'd like this memory to be always billed to the root cgroup, - * not to the process removing the memcg. While kmalloc would - * require us to wrap it into memcg_stop/resume_kmem_account, - * with __get_free_pages we just don't pass the memcg flag. - */ - memcg->memcg_name = (char *)__get_free_pages(GFP_KERNEL, 0); - - /* - * we will, in general, just ignore failures. No need to go crazy, - * being this just a debugging interface. It is nice to copy a memcg - * name over, but if we (unlikely) can't, just the address will do - */ - if (!memcg->memcg_name) - goto add_list; - - if (cgroup_path(memcg->css.cgroup, memcg->memcg_name, PAGE_SIZE) < 0) { - free_pages((unsigned long)memcg->memcg_name, 0); - memcg->memcg_name = NULL; - } - -add_list: INIT_LIST_HEAD(&memcg->dead); mutex_lock(&dangling_memcgs_mutex); list_add(&memcg->dead, &dangling_memcgs); @@ -5188,12 +5154,28 @@ static int mem_cgroup_dangling_read(struct cgroup *cont, struct cftype *cft, struct seq_file *m) { struct mem_cgroup *memcg; + char *memcg_name; + int ret; + + /* + * cgroup.c will do page-sized allocations most of the time, + * so we'll just follow the pattern. Also, __get_free_pages + * is a better interface than kmalloc for us here, because + * we'd like this memory to be always billed to the root cgroup, + * not to the process removing the memcg. While kmalloc would + * require us to wrap it into memcg_stop/resume_kmem_account, + * with __get_free_pages we just don't pass the memcg flag. + */ + memcg_name = (char *)__get_free_pages(GFP_KERNEL, 0); + if (!memcg_name) + return -ENOMEM; mutex_lock(&dangling_memcgs_mutex); list_for_each_entry(memcg, &dangling_memcgs, dead) { - if (memcg->memcg_name) - seq_printf(m, "%s:\n", memcg->memcg_name); + ret = cgroup_path(memcg->css.cgroup, memcg_name, PAGE_SIZE); + if (!ret) + seq_printf(m, "%s:\n", memcg_name); else seq_printf(m, "%p (name lost):\n", memcg); @@ -5203,6 +5185,7 @@ static int mem_cgroup_dangling_read(struct cgroup *cont, struct cftype *cft, } mutex_unlock(&dangling_memcgs_mutex); + free_pages((unsigned long)memcg_name, 0); return 0; } #endif -- 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/