sky2: no recycling

Recycling turns out to be a bad idea!  For most use cases, the
packet can not be reused: TCP packets are cloned. Even for the ideal
case of forwarding, it hurts performance because of CPU ping/pong.
On a multi-core system forwarding of 64 byte packets is worse
much worse: recycling = 24% forwarded vs no recycling = 42% forwarded

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index a3e40d7..1b79d33 100644 (file)
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1177,7 +1177,6 @@ static void sky2_rx_clean(struct sky2_port *sky2)
                        re->skb = NULL;
                }
        }
-       skb_queue_purge(&sky2->rx_recycle);
 }
 
 /* Basic MII support */
@@ -1269,10 +1268,8 @@ static struct sk_buff *sky2_rx_alloc(struct sky2_port *sky2)
        struct sk_buff *skb;
        int i;
 
-       skb = __skb_dequeue(&sky2->rx_recycle);
-       if (!skb)
-               skb = netdev_alloc_skb(sky2->netdev, sky2->rx_data_size
-                                      + sky2_rx_pad(sky2->hw));
+       skb = netdev_alloc_skb(sky2->netdev,
+                              sky2->rx_data_size + sky2_rx_pad(sky2->hw));
        if (!skb)
                goto nomem;
 
@@ -1364,8 +1361,6 @@ static int sky2_rx_start(struct sky2_port *sky2)
 
        sky2->rx_data_size = size;
 
-       skb_queue_head_init(&sky2->rx_recycle);
-
        /* Fill Rx ring */
        for (i = 0; i < sky2->rx_pending; i++) {
                re = sky2->rx_ring + i;
@@ -1776,12 +1771,7 @@ static void sky2_tx_complete(struct sky2_port *sky2, u16 done)
                        dev->stats.tx_packets++;
                        dev->stats.tx_bytes += skb->len;
 
-                       if (skb_queue_len(&sky2->rx_recycle) < sky2->rx_pending
-                           && skb_recycle_check(skb, sky2->rx_data_size
-                                                + sky2_rx_pad(sky2->hw)))
-                               __skb_queue_head(&sky2->rx_recycle, skb);
-                       else
-                               dev_kfree_skb_any(skb);
+                       dev_kfree_skb_any(skb);
 
                        sky2->tx_next = RING_NEXT(idx, sky2->tx_ring_size);
                }

diff --git a/drivers/net/sky2.h b/drivers/net/sky2.h
index 9d07a46..73c9547 100644 (file)
--- a/drivers/net/sky2.h
+++ b/drivers/net/sky2.h
@@ -2032,7 +2032,6 @@ struct sky2_port {
        u16                  rx_pending;
        u16                  rx_data_size;
        u16                  rx_nfrags;
-       struct sk_buff_head  rx_recycle;
 
 #ifdef SKY2_VLAN_TAG_USED
        u16                  rx_tag;