xen/netfront: remove unnecessary wmb

RING_PUSH_REQUESTS_AND_CHECK_NOTIFY is already able to make sure backend sees
requests before req_prod is updated.

Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index f17f602e6171203acd39ee448c305cba719ff1de..a8303afa15f15723244e171860fe3dac074efb1c 100644 (file)
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -337,8 +337,6 @@ static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
                return;
        }
 
-       wmb();          /* barrier so backend seens requests */
-
        RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
        if (notify)
                notify_remote_via_irq(queue->rx_irq);