[NET] front: Move rx req pushing to one spot

This patch moves all rx request pushing to network_alloc_rx_buffers.
This is needed to reduce churn for TSO.  More importantly, this makes
it easier to send notifications when adding rx requests which is
required for having a queue in dom0.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
index 41fddd04b0861c50d2b929979f764a819bf09964..77921f081dcfc1ceb2db76d77618da577ad70815 100644 (file)
--- a/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c
@@ -600,14 +600,17 @@ static void network_alloc_rx_buffers(struct net_device *dev)
                        /* Could not allocate any skbuffs. Try again later. */
                        mod_timer(&np->rx_refill_timer,
                                  jiffies + (HZ/10));
-                       return;
+                       break;
                }
                __skb_queue_tail(&np->rx_batch, skb);
        }
 
        /* Is the batch large enough to be worthwhile? */
-       if (i < (np->rx_target/2))
+       if (i < (np->rx_target/2)) {
+               if (req_prod > np->rx.sring->req_prod)
+                       goto push;
                return;
+       }
 
        /* Adjust our fill target if we risked running out of buffers. */
        if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) &&
@@ -678,6 +681,7 @@ static void network_alloc_rx_buffers(struct net_device *dev)
 
        /* Above is a suitable barrier to ensure backend will see requests. */
        np->rx.req_prod_pvt = req_prod + i;
+ push:
        RING_PUSH_REQUESTS(&np->rx);
 }
 
@@ -875,7 +879,6 @@ static void xennet_move_rx_slot(struct netfront_info *np, struct sk_buff *skb,
        RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
        RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
        np->rx.req_prod_pvt++;
-       RING_PUSH_REQUESTS(&np->rx);
 }
 
 static int netif_poll(struct net_device *dev, int *pbudget)
@@ -1207,7 +1210,6 @@ static void network_connect(struct net_device *dev)
        }
 
        np->rx.req_prod_pvt = requeue_idx;
-       RING_PUSH_REQUESTS(&np->rx);
 
        /*
         * Step 3: All public and private state should now be sane.  Get