From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 4/4] memcg: force use_hierarchy if sane_behavior Date: Fri, 12 Apr 2013 16:10:59 -0700 Message-ID: <1365808259-31073-5-git-send-email-tj@kernel.org> References: <1365808259-31073-1-git-send-email-tj@kernel.org> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:sender:from:to:cc:subject:date:message-id:x-mailer :in-reply-to:references; bh=F/AiwxqjTnlYwuOIYffHvQP5G1jWErcoltPA9VyTpd4=; b=quGVC50F6Nb7gYWmo1F5U6sKjeUlTIyMSxtx9POCb9R+oc5n3Ul4cnfiVQqu/mYHoT iZ/gc3BVMTeMOL1Y1CVFyiXb+oMfJPXYaNNIDMKjguwmtqSlxgA8MYa+Y/H/QdUDv33y r417xOGYDNN3YYSZWZwFMPbtsHD+fX5wxcbhIqI+77K3ITfVwmYfWwjZc9zciFJ24TL2 8E9P3cpgbcQQIqRVboom87/W/JOliKwWG9ztriv+liO5LseRkVG1X6PvbKQsoT97dzC3 wyRRfYU4puGf9dn0nHjN/xrrHzYREfeinB+GRMGQDI32ULCrJWVGT6YewH2pUpT8at8r TuXg== In-Reply-To: <1365808259-31073-1-git-send-email-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lizefan@huawei.com Cc: containers@lists.linux-foundation.org, cgroups@vger.kernel.org, mhocko@suse.cz, kamezawa.hiroyu@jp.fujitsu.com, linux-kernel@vger.kernel.org, glommer@parallels.com, vgoyal@redhat.com, Tejun Heo Turn on use_hierarchy by default if sane_behavior is specified and don't create .use_hierarchy file. It is debatable whether to remove .use_hierarchy file or make it ro as the former could make transition easier in certain cases; however, the behavior changes which will be gated by sane_behavior are intensive including changing basic meaning of certain control knobs in a few controllers and I don't really think keeping this piece would make things easier in any noticeable way, so let's remove it. Signed-off-by: Tejun Heo Cc: Michal Hocko Cc: KAMEZAWA Hiroyuki --- include/linux/cgroup.h | 3 +++ mm/memcontrol.c | 13 +++++++++++++ 2 files changed, 16 insertions(+) diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 9c300ad..c562e33 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -269,6 +269,9 @@ enum { * * - Remount is disallowed. * + * - memcg: use_hierarchy is on by default and the cgroup file for + * the flag is not created. + * * The followings are planned changes. * * - release_agent will be disallowed once replacement notification diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9715c0c..a651131 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5814,6 +5814,7 @@ static struct cftype mem_cgroup_files[] = { }, { .name = "use_hierarchy", + .flags = CFTYPE_INSANE, .write_u64 = mem_cgroup_hierarchy_write, .read_u64 = mem_cgroup_hierarchy_read, }, @@ -6784,6 +6785,17 @@ static void mem_cgroup_move_task(struct cgroup *cont, } #endif +/* + * Cgroup retains root cgroups across [un]mount cycles making it necessary + * to verify sane_behavior flag on each mount attempt. + */ +static void mem_cgroup_bind(struct cgroup *root) +{ + /* use_hierarchy is forced with sane_behavior */ + if (cgroup_sane_behavior(root)) + mem_cgroup_from_cont(root)->use_hierarchy = true; +} + struct cgroup_subsys mem_cgroup_subsys = { .name = "memory", .subsys_id = mem_cgroup_subsys_id, @@ -6794,6 +6806,7 @@ struct cgroup_subsys mem_cgroup_subsys = { .can_attach = mem_cgroup_can_attach, .cancel_attach = mem_cgroup_cancel_attach, .attach = mem_cgroup_move_task, + .bind = mem_cgroup_bind, .base_cftypes = mem_cgroup_files, .early_init = 0, .use_id = 1, -- 1.8.1.4