virtio_net: delay TX callbacks

Ask for delayed callbacks on TX ring full, to give the
other side more of a chance to make progress.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0cb0b06..f685324 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -609,7 +609,7 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev)
         * before it gets out of hand.  Naturally, this wastes entries. */
        if (capacity < 2+MAX_SKB_FRAGS) {
                netif_stop_queue(dev);
-               if (unlikely(!virtqueue_enable_cb(vi->svq))) {
+               if (unlikely(!virtqueue_enable_cb_delayed(vi->svq))) {
                        /* More just got used, free them then recheck. */
                        capacity += free_old_xmit_skbs(vi);
                        if (capacity >= 2+MAX_SKB_FRAGS) {