static struct futex_hash_bucket *hash_futex(union futex_key *key)
{
	u32 hash = jhash2((u32*)&key->both.word,
			  (sizeof(key->both.word)+sizeof(key->both.ptr))/4,
			  key->both.offset);
	return &futex_queues[hash & ((1 << FUTEX_HASHBITS)-1)];
}