static bool cgroup_is_valid_domain(struct cgroup *cgrp)
{
	/* the cgroup itself can be a thread root */
	if (cgroup_is_threaded(cgrp))
		return false;

	/* but the ancestors can't be unless mixable */
	while ((cgrp = cgroup_parent(cgrp))) {
		if (!cgroup_is_mixable(cgrp) && cgroup_is_thread_root(cgrp))
			return false;
		if (cgroup_is_threaded(cgrp))
			return false;
	}

	return true;
}
static bool cgroup_is_valid_domain(struct cgroup *cgrp)
{
	 
	if (cgroup_is_threaded(cgrp))
		return false;

	 
	while ((cgrp = cgroup_parent(cgrp))) {
		if (!cgroup_is_mixable(cgrp) && cgroup_is_thread_root(cgrp))
			return false;
		if (cgroup_is_threaded(cgrp))
			return false;
	}

	return true;
}