virtio_net: remove send queue

Now we have a virtio detach API (in commit
f9bfbebf34eab707b065116cdc9699d25ba4252a), we don't need to track xmit
skbs in the virio_net driver, which improves transmission performance.

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

1 files changed, 8 insertions, 18 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 4c347a3df657..ce35b42cc2cb 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -56,9 +56,6 @@ struct virtnet_info
         /* Host will merge rx buffers for big packets (shake it! shake it!) */
         bool mergeable_rx_bufs;
 
-        /* Send queue. */
-        struct sk_buff_head send;
-
         /* Work struct for refilling if we run low on memory. */
         struct delayed_work refill;
 
@@ -505,7 +502,6 @@ static unsigned int free_old_xmit_skbs(struct virtnet_info *vi)
 
         while ((skb = vi->svq->vq_ops->get_buf(vi->svq, &len)) != NULL) {
                 pr_debug("Sent skb %p\n", skb);
-                __skb_unlink(skb, &vi->send);
                 vi->dev->stats.tx_bytes += skb->len;
                 vi->dev->stats.tx_packets++;
                 tot_sgs += skb_vnet_hdr(skb)->num_sg;
@@ -588,15 +584,6 @@ again:
         }
         vi->svq->vq_ops->kick(vi->svq);
 
-        /*
-         * Put new one in send queue.  You'd expect we'd need this before
-         * xmit_skb calls add_buf(), since the callback can be triggered
-         * immediately after that.  But since the callback just triggers
-         * another call back here, normal network xmit locking prevents the
-         * race.
-         */
-        __skb_queue_head(&vi->send, skb);
-
         /* Don't wait up for transmitted skbs to be freed. */
         skb_orphan(skb);
         nf_reset(skb);
@@ -980,9 +967,6 @@ static int virtnet_probe(struct virtio_device *vdev)
                         dev->features |= NETIF_F_HW_VLAN_FILTER;
         }
 
-        /* Initialize our empty send queue. */
-        skb_queue_head_init(&vi->send);
-
         err = register_netdev(dev);
         if (err) {
                 pr_debug("virtio_net: registering device failed\n");
@@ -1019,6 +1003,12 @@ static void free_unused_bufs(struct virtnet_info *vi)
 {
         void *buf;
         while (1) {
+                buf = vi->svq->vq_ops->detach_unused_buf(vi->svq);
+                if (!buf)
+                        break;
+                dev_kfree_skb(buf);
+        }
+        while (1) {
                 buf = vi->rvq->vq_ops->detach_unused_buf(vi->rvq);
                 if (!buf)
                         break;
@@ -1038,11 +1028,11 @@ static void __devexit virtnet_remove(struct virtio_device *vdev)
         /* Stop all the virtqueues. */
         vdev->config->reset(vdev);
 
-        /* Free our skbs in send queue, if any. */
-        __skb_queue_purge(&vi->send);
 
         unregister_netdev(vi->dev);
         cancel_delayed_work_sync(&vi->refill);
+
+        /* Free unused buffers in both send and recv, if any. */
         free_unused_bufs(vi);
 
         vdev->config->del_vqs(vi->vdev);