igb: flush when in xmit_more mode and under descriptor pressure

Mirror the changes made to ixgbe in commit 2367a17390138f68b3aa28f2f220b8d7ff8d91f4
("ixgbe: flush when in xmit_more mode and under descriptor pressure")

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 89c29b40d61c8a4e08ff52cce6d5c26c81b9fed4..89de7fee5e9413a59aec095ad8c44a032c138b18 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -4813,6 +4813,41 @@ static void igb_tx_olinfo_status(struct igb_ring *tx_ring,
        tx_desc->read.olinfo_status = cpu_to_le32(olinfo_status);
 }
 
+static int __igb_maybe_stop_tx(struct igb_ring *tx_ring, const u16 size)
+{
+       struct net_device *netdev = tx_ring->netdev;
+
+       netif_stop_subqueue(netdev, tx_ring->queue_index);
+
+       /* Herbert's original patch had:
+        *  smp_mb__after_netif_stop_queue();
+        * but since that doesn't exist yet, just open code it.
+        */
+       smp_mb();
+
+       /* We need to check again in a case another CPU has just
+        * made room available.
+        */
+       if (igb_desc_unused(tx_ring) < size)
+               return -EBUSY;
+
+       /* A reprieve! */
+       netif_wake_subqueue(netdev, tx_ring->queue_index);
+
+       u64_stats_update_begin(&tx_ring->tx_syncp2);
+       tx_ring->tx_stats.restart_queue2++;
+       u64_stats_update_end(&tx_ring->tx_syncp2);
+
+       return 0;
+}
+
+static inline int igb_maybe_stop_tx(struct igb_ring *tx_ring, const u16 size)
+{
+       if (igb_desc_unused(tx_ring) >= size)
+               return 0;
+       return __igb_maybe_stop_tx(tx_ring, size);
+}
+
 static void igb_tx_map(struct igb_ring *tx_ring,
                       struct igb_tx_buffer *first,
                       const u8 hdr_len)
@@ -4915,7 +4950,10 @@ static void igb_tx_map(struct igb_ring *tx_ring,
 
        tx_ring->next_to_use = i;
 
-       if (!skb->xmit_more) {
+       /* Make sure there is space in the ring for the next send. */
+       igb_maybe_stop_tx(tx_ring, DESC_NEEDED);
+
+       if (netif_xmit_stopped(txring_txq(tx_ring)) || !skb->xmit_more) {
                writel(i, tx_ring->tail);
 
                /* we need this if more than one processor can write to our tail
@@ -4942,41 +4980,6 @@ dma_error:
        tx_ring->next_to_use = i;
 }
 
-static int __igb_maybe_stop_tx(struct igb_ring *tx_ring, const u16 size)
-{
-       struct net_device *netdev = tx_ring->netdev;
-
-       netif_stop_subqueue(netdev, tx_ring->queue_index);
-
-       /* Herbert's original patch had:
-        *  smp_mb__after_netif_stop_queue();
-        * but since that doesn't exist yet, just open code it.
-        */
-       smp_mb();
-
-       /* We need to check again in a case another CPU has just
-        * made room available.
-        */
-       if (igb_desc_unused(tx_ring) < size)
-               return -EBUSY;
-
-       /* A reprieve! */
-       netif_wake_subqueue(netdev, tx_ring->queue_index);
-
-       u64_stats_update_begin(&tx_ring->tx_syncp2);
-       tx_ring->tx_stats.restart_queue2++;
-       u64_stats_update_end(&tx_ring->tx_syncp2);
-
-       return 0;
-}
-
-static inline int igb_maybe_stop_tx(struct igb_ring *tx_ring, const u16 size)
-{
-       if (igb_desc_unused(tx_ring) >= size)
-               return 0;
-       return __igb_maybe_stop_tx(tx_ring, size);
-}
-
 netdev_tx_t igb_xmit_frame_ring(struct sk_buff *skb,
                                struct igb_ring *tx_ring)
 {
@@ -5047,9 +5050,6 @@ netdev_tx_t igb_xmit_frame_ring(struct sk_buff *skb,
 
        igb_tx_map(tx_ring, first, hdr_len);
 
-       /* Make sure there is space in the ring for the next send. */
-       igb_maybe_stop_tx(tx_ring, DESC_NEEDED);
-
        return NETDEV_TX_OK;
 
 out_drop: