From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: [PATCH] cgroup: disallow disabled controllers on the default hierarchy Date: Thu, 5 Jun 2014 17:16:30 +0800 Message-ID: <5390356E.70305@huawei.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo Cc: LKML , Cgroups , Michal Hocko , Johannes Weiner After booting with cgroup_disable=memory, I still saw memcg files in the default hierarchy, and I can write to them, though it won't take effect. # dmesg ... Disabling memory control group subsystem ... # mount -t cgroup -o __DEVEL__sane_behavior xxx /cgroup # ls /cgroup ... memory.failcnt memory.move_charge_at_immigrate memory.force_empty memory.numa_stat memory.limit_in_bytes memory.oom_control ... # cat /cgroup/memory.usage_in_bytes 0 Signed-off-by: Li Zefan --- kernel/cgroup.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index d5032d2..57b647a 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3070,6 +3070,9 @@ int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts) { int ret; + if (ss->disabled) + return 0; + if (!cfts || cfts[0].name[0] == '\0') return 0; @@ -4679,8 +4682,6 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early) BUG_ON(online_css(css)); - cgrp_dfl_root.subsys_mask |= 1 << ss->id; - mutex_unlock(&cgroup_mutex); } @@ -4760,10 +4761,13 @@ int __init cgroup_init(void) /* * cftype registration needs kmalloc and can't be done - * during early_init. Register base cftypes separately. + * during early_init, and the disable flag is set after + * early_init. Register base cftypes separately. */ - if (ss->base_cftypes) + if (!ss->disabled) { + cgrp_dfl_root.subsys_mask |= 1 << ss->id; WARN_ON(cgroup_add_cftypes(ss, ss->base_cftypes)); + } } cgroup_kobj = kobject_create_and_add("cgroup", fs_kobj); -- 1.8.0.2