Commit 3a5db0b1 authored Nov 27, 2017 by Paul E. McKenney

drivers/vhost: Remove now-redundant read_barrier_depends()

Because READ_ONCE() now implies read_barrier_depends(), the
read_barrier_depends() in next_desc() is now redundant.  This commit
therefore removes it and the related comments.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: <kvm@vger.kernel.org>
Cc: <virtualization@lists.linux-foundation.org>
Cc: <netdev@vger.kernel.org>

parent 91db2592

drivers/vhost/vhost.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -1877,12 +1877,7 @@ static unsigned next_desc(struct vhost_virtqueue vq, struct vring_desc desc)
		return -1U;

		/* Check they're not leading us off end of descriptors. */
		next = vhost16_to_cpu(vq, desc->next);
		/* Make sure compiler knows to grab that: we don't want it changing! */
		/* We will use the result as an index in an array, so most
		* architectures only need a compiler barrier here. */
		read_barrier_depends();

		next = vhost16_to_cpu(vq, READ_ONCE(desc->next));
		return next;
		}