In commit: a292ca6efbc1f259ddfb9c902367f2588e0e8b0f
to e1000_main.c, there is the change below.
I am curious why the skb_put no longer subtracts ETHERNET_FCS_SIZE
from the length. Is the idea that we will now always include the
FCS at the end of the skb?
It also seems that the skb_put for the else clause is missing here, but
I think it is fixed in some later patch.
The main reason I ask is that I have a patch that enabled reception of the
FCS in 2.6.13. It used a flag to determine whether to subtract the
ETHERNET_FCS_SIZE
from length (or not, if we are capturing FCS). I am trying to figure out if
this
is still needed in the later releases.
Thanks,
Ben
@@ -3613,17 +3618,40 @@ #endif
}
}
- /* Good Receive */
- skb_put(skb, length - ETHERNET_FCS_SIZE);
+ /* code added for copybreak, this should improve
+ * performance for small packets with large amounts
+ * of reassembly being done in the stack */
+#define E1000_CB_LENGTH 256
+ if ((length < E1000_CB_LENGTH) &&
+ !rx_ring->rx_skb_top &&
+ /* or maybe (status & E1000_RXD_STAT_EOP) && */
+ !multi_descriptor) {
+ struct sk_buff *new_skb =
+ dev_alloc_skb(length + NET_IP_ALIGN);
+ if (new_skb) {
+ skb_reserve(new_skb, NET_IP_ALIGN);
+ new_skb->dev = netdev;
+ memcpy(new_skb->data - NET_IP_ALIGN,
+ skb->data - NET_IP_ALIGN,
+ length + NET_IP_ALIGN);
+ /* save the skb in buffer_info as good */
+ buffer_info->skb = skb;
+ skb = new_skb;
+ skb_put(skb, length);
+ }
+ }
+
+ /* end copybreak code */
--
Ben Greear <[EMAIL PROTECTED]>
Candela Technologies Inc http://www.candelatech.com
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