From 8d86c61ae41d9068fd5e5cc01a4abd53c4fe3ab5 Mon Sep 17 00:00:00 2001
From: Santiago Leon <santil@linux.vnet.ibm.com>
Date: Fri, 3 Sep 2010 18:28:25 +0000
Subject: [PATCH] ibmveth: Add rx_copybreak
For small packets, create a new skb and copy the packet into it so we
avoid tearing down and creating a TCE entry.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Santiago Leon <santil@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/ibmveth.c | 29 +++++++++++++++++++++++------
1 file changed, 23 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ibmveth.c b/drivers/net/ibmveth.c
index fc6e2cf879c0..c236c8af3367 100644
--- a/drivers/net/ibmveth.c
+++ b/drivers/net/ibmveth.c
@@ -122,6 +122,11 @@ module_param(tx_copybreak, uint, 0644);
MODULE_PARM_DESC(tx_copybreak,
"Maximum size of packet that is copied to a new buffer on transmit");
+static unsigned int rx_copybreak __read_mostly = 128;
+module_param(rx_copybreak, uint, 0644);
+MODULE_PARM_DESC(rx_copybreak,
+ "Maximum size of packet that is copied to a new buffer on receive");
+
struct ibmveth_stat {
char name[ETH_GSTRING_LEN];
int offset;
@@ -1002,8 +1007,6 @@ static int ibmveth_poll(struct napi_struct *napi, int budget)
restart_poll:
do {
- struct sk_buff *skb;
-
if (!ibmveth_rxq_pending_buffer(adapter))
break;
@@ -1014,20 +1017,34 @@ static int ibmveth_poll(struct napi_struct *napi, int budget)
ibmveth_debug_printk("recycling invalid buffer\n");
ibmveth_rxq_recycle_buffer(adapter);
} else {
+ struct sk_buff *skb, *new_skb;
int length = ibmveth_rxq_frame_length(adapter);
int offset = ibmveth_rxq_frame_offset(adapter);
int csum_good = ibmveth_rxq_csum_good(adapter);
skb = ibmveth_rxq_get_buffer(adapter);
- if (csum_good)
- skb->ip_summed = CHECKSUM_UNNECESSARY;
- ibmveth_rxq_harvest_buffer(adapter);
+ new_skb = NULL;
+ if (length < rx_copybreak)
+ new_skb = netdev_alloc_skb(netdev, length);
+
+ if (new_skb) {
+ skb_copy_to_linear_data(new_skb,
+ skb->data + offset,
+ length);
+ skb = new_skb;
+ ibmveth_rxq_recycle_buffer(adapter);
+ } else {
+ ibmveth_rxq_harvest_buffer(adapter);
+ skb_reserve(skb, offset);
+ }
- skb_reserve(skb, offset);
skb_put(skb, length);
skb->protocol = eth_type_trans(skb, netdev);
+ if (csum_good)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
netif_receive_skb(skb); /* send it up */
netdev->stats.rx_packets++;
--
GitLab