1 files changed, 22 insertions, 23 deletions

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index fff8cddfed81..301cc037fda8 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -47,11 +47,6 @@ int xenvif_schedulable(struct xenvif *vif)
         return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
 }
 
-static int xenvif_rx_schedulable(struct xenvif *vif)
-{
-        return xenvif_schedulable(vif) && !xenvif_rx_ring_full(vif);
-}
-
 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
 {
         struct xenvif *vif = dev_id;
@@ -105,8 +100,7 @@ static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
 {
         struct xenvif *vif = dev_id;
 
-        if (xenvif_rx_schedulable(vif))
-                netif_wake_queue(vif->dev);
+        xenvif_kick_thread(vif);
 
         return IRQ_HANDLED;
 }
@@ -122,24 +116,34 @@ static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
+        int min_slots_needed;
 
         BUG_ON(skb->dev != dev);
 
         /* Drop the packet if vif is not ready */
-        if (vif->task == NULL)
+        if (vif->task == NULL || !xenvif_schedulable(vif))
                 goto drop;
 
-        /* Drop the packet if the target domain has no receive buffers. */
-        if (!xenvif_rx_schedulable(vif))
-                goto drop;
+        /* At best we'll need one slot for the header and one for each
+         * frag.
+         */
+        min_slots_needed = 1 + skb_shinfo(skb)->nr_frags;
 
-        /* Reserve ring slots for the worst-case number of fragments. */
-        vif->rx_req_cons_peek += xenvif_count_skb_slots(vif, skb);
+        /* If the skb is GSO then we'll also need an extra slot for the
+         * metadata.
+         */
+        if (skb_is_gso(skb))
+                min_slots_needed++;
 
-        if (vif->can_queue && xenvif_must_stop_queue(vif))
-                netif_stop_queue(dev);
+        /* If the skb can't possibly fit in the remaining slots
+         * then turn off the queue to give the ring a chance to
+         * drain.
+         */
+        if (!xenvif_rx_ring_slots_available(vif, min_slots_needed))
+                xenvif_stop_queue(vif);
 
-        xenvif_queue_tx_skb(vif, skb);
+        skb_queue_tail(&vif->rx_queue, skb);
+        xenvif_kick_thread(vif);
 
         return NETDEV_TX_OK;
 
@@ -149,12 +153,6 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
         return NETDEV_TX_OK;
 }
 
-void xenvif_notify_tx_completion(struct xenvif *vif)
-{
-        if (netif_queue_stopped(vif->dev) && xenvif_rx_schedulable(vif))
-                netif_wake_queue(vif->dev);
-}
-
 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
 {
         struct xenvif *vif = netdev_priv(dev);
@@ -388,6 +386,8 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
         if (err < 0)
                 goto err;
 
+        init_waitqueue_head(&vif->wq);
+
         if (tx_evtchn == rx_evtchn) {
                 /* feature-split-event-channels == 0 */
                 err = bind_interdomain_evtchn_to_irqhandler(
@@ -420,7 +420,6 @@ int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
                 disable_irq(vif->rx_irq);
         }
 
-        init_waitqueue_head(&vif->wq);
         task = kthread_create(xenvif_kthread,
                               (void *)vif, "%s", vif->dev->name);
         if (IS_ERR(task)) {