cgroup: disallow disabled controllers on the default hierarchy (c731ae1d) · Commits · 戴 / test

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 tj: Minor comment update. Signed-off-by:

Li Zefan <lizefan@huawei.com> Signed-off-by:

Tejun Heo <tj@kernel.org>

kernel/cgroup.c

+9 −5

Original line number	Diff line number	Diff line
		@@ -3069,6 +3069,9 @@ 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;

		@@ -4678,8 +4681,6 @@ 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);
		}

		@@ -4758,12 +4759,15 @@ int __init cgroup_init(void)
		&cgrp_dfl_root.cgrp.e_csets[ssid]);

		/*
		* cftype registration needs kmalloc and can't be done
		* during early_init. Register base cftypes separately.
		* Setting dfl_root subsys_mask needs to consider the
		* disabled flag and cftype registration needs kmalloc,
		* both of which aren't available during early_init.
		*/
		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);
		if (!cgroup_kobj)

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