Commit 9121e478 authored by Darren Hart's avatar Darren Hart Committed by Thomas Gleixner
Browse files

futex: distangle futex_requeue()



futex_requeue() is getting a bit long-winded, and will be getting more
so after the requeue_pi patch. Factor out the actual requeueing into a
nicely contained inline function to reduce function length and improve
legibility.

Signed-off-by: default avatarDarren Hart <dvhltc@us.ibm.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent a72188d8
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+29 −14
Original line number Diff line number Diff line
@@ -940,6 +940,34 @@ out:
	return ret;
}

/**
 * requeue_futex() - Requeue a futex_q from one hb to another
 * @q:		the futex_q to requeue
 * @hb1:	the source hash_bucket
 * @hb2:	the target hash_bucket
 * @key2:	the new key for the requeued futex_q
 */
static inline
void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
		   struct futex_hash_bucket *hb2, union futex_key *key2)
{

	/*
	 * If key1 and key2 hash to the same bucket, no need to
	 * requeue.
	 */
	if (likely(&hb1->chain != &hb2->chain)) {
		plist_del(&q->list, &hb1->chain);
		plist_add(&q->list, &hb2->chain);
		q->lock_ptr = &hb2->lock;
#ifdef CONFIG_DEBUG_PI_LIST
		q->list.plist.lock = &hb2->lock;
#endif
	}
	get_futex_key_refs(key2);
	q->key = *key2;
}

/*
 * Requeue all waiters hashed on one physical page to another
 * physical page.
@@ -999,20 +1027,7 @@ retry_private:
		if (++ret <= nr_wake) {
			wake_futex(this);
		} else {
			/*
			 * If key1 and key2 hash to the same bucket, no need to
			 * requeue.
			 */
			if (likely(head1 != &hb2->chain)) {
				plist_del(&this->list, &hb1->chain);
				plist_add(&this->list, &hb2->chain);
				this->lock_ptr = &hb2->lock;
#ifdef CONFIG_DEBUG_PI_LIST
				this->list.plist.lock = &hb2->lock;
#endif
			}
			this->key = key2;
			get_futex_key_refs(&key2);
			requeue_futex(this, hb1, hb2, &key2);
			drop_count++;

			if (ret - nr_wake >= nr_requeue)