From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx137.postini.com [74.125.245.137]) by kanga.kvack.org (Postfix) with SMTP id 747166B0071 for ; Fri, 7 Dec 2012 12:12:26 -0500 (EST) Received: by mail-da0-f41.google.com with SMTP id e20so301753dak.14 for ; Fri, 07 Dec 2012 09:12:25 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20121207085839.GB31938@dhcp22.suse.cz> References: <1353955671-14385-1-git-send-email-mhocko@suse.cz> <1353955671-14385-4-git-send-email-mhocko@suse.cz> <20121207085839.GB31938@dhcp22.suse.cz> Date: Fri, 7 Dec 2012 09:12:25 -0800 Message-ID: Subject: Re: [patch v2 3/6] memcg: rework mem_cgroup_iter to use cgroup iterators From: Ying Han Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, KAMEZAWA Hiroyuki , Johannes Weiner , Tejun Heo , Glauber Costa , Li Zefan On Fri, Dec 7, 2012 at 12:58 AM, Michal Hocko wrote: > On Thu 06-12-12 19:43:52, Ying Han wrote: > [...] >> Forgot to mention, I was testing 3.7-rc6 with the two cgroup changes : > > Could you give a try to -mm tree as well. There are some changes for > memcgs removal in that tree which are not in Linus's tree. I will give a try, which patchset you have in mind so i can double check? I didn't find the place where the css pins the memcg, which either something i missed or not in place in my tree. I twisted the patch a bit to make it closer to your v2 version, but instead keep the mem_cgroup_put() as well as using css_tryget(). Again, my test is happy with it: diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f2eeee6..acec05a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1004,6 +1004,7 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, if (prev && reclaim->generation != iter->generation) { if (last_visited) { css_put(&last_visited->css); + mem_cgroup_put(last_visited); iter->last_visited = NULL; } spin_unlock(&iter->iter_lock); @@ -1041,15 +1042,22 @@ struct mem_cgroup *mem_cgroup_iter(struct mem_cgroup *root, if (reclaim) { struct mem_cgroup *curr = memcg; - if (last_visited) + if (last_visited) { css_put(&last_visited->css); + mem_cgroup_put(last_visited); + } if (css && !memcg) curr = container_of(css, struct mem_cgroup, css); /* make sure that the cached memcg is not removed */ - if (curr) - css_get(&curr->css); + if (curr) { + mem_cgroup_get(curr); + if (!css_tryget(&curr->css)) { + mem_cgroup_put(curr); + curr = NULL; + } + } iter->last_visited = curr; if (!css) --Ying > -- > Michal Hocko > SUSE Labs -- 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