static inline void free_signal_struct(struct signal_struct *sig)
{
	taskstats_tgid_free(sig);
	sched_autogroup_exit(sig);
	/*
	 * __mmdrop is not safe to call from softirq context on x86 due to
	 * pgd_dtor so postpone it to the async context
	 */
	if (sig->oom_mm)
		mmdrop_async(sig->oom_mm);
	kmem_cache_free(signal_cachep, sig);
}