void cgroup_file_notify(struct cgroup_file *cfile)
{
	unsigned long flags;

	spin_lock_irqsave(&cgroup_file_kn_lock, flags);
	if (cfile->kn) {
		unsigned long last = cfile->notified_at;
		unsigned long next = last + CGROUP_FILE_NOTIFY_MIN_INTV;

		if (time_in_range(jiffies, last, next)) {
			timer_reduce(&cfile->notify_timer, next);
		} else {
			kernfs_notify(cfile->kn);
			cfile->notified_at = jiffies;
		}
	}
	spin_unlock_irqrestore(&cgroup_file_kn_lock, flags);
}
void cgroup_file_notify(struct cgroup_file *cfile)
{
	unsigned long flags;

	spin_lock_irqsave(&cgroup_file_kn_lock, flags);
	if (cfile->kn) {
		unsigned long last = cfile->notified_at;
		unsigned long next = last + CGROUP_FILE_NOTIFY_MIN_INTV;

		if (time_in_range(jiffies, last, next)) {
			timer_reduce(&cfile->notify_timer, next);
		} else {
			kernfs_notify(cfile->kn);
			cfile->notified_at = jiffies;
		}
	}
	spin_unlock_irqrestore(&cgroup_file_kn_lock, flags);
}