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 <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 33ac2b186b85eb1f4883d26d6d0d9b3a8532fc01..78b5940a415a83bb6b3cc83be59f8ebf263ccb78 100644 (file)
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -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;
 }