tip-bot for Paul E. McKenney
2018-Jan-03 16:08 UTC
[tip:core/rcu] drivers/vhost: Remove now-redundant read_barrier_depends()
Commit-ID: 3a5db0b108e0a40f08c2bcff6a675dbf632b91e0 Gitweb: https://git.kernel.org/tip/3a5db0b108e0a40f08c2bcff6a675dbf632b91e0 Author: Paul E. McKenney <paulmck at linux.vnet.ibm.com> AuthorDate: Mon, 27 Nov 2017 09:45:10 -0800 Committer: Paul E. McKenney <paulmck at linux.vnet.ibm.com> CommitDate: Tue, 5 Dec 2017 11:57:55 -0800 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 at linux.vnet.ibm.com> Cc: "Michael S. Tsirkin" <mst at redhat.com> Cc: Jason Wang <jasowang at redhat.com> Cc: <kvm at vger.kernel.org> Cc: <virtualization at lists.linux-foundation.org> Cc: <netdev at vger.kernel.org> --- drivers/vhost/vhost.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 33ac2b1..78b5940 100644 --- 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; }