[PATCH] ixgb: Code optimization
Code optimization
Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Ganesh Venkatesan <ganesh.venkatesan@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
diff -up net-drivers-2.6/drivers/net/ixgb/ixgb_main.c net-drivers-2.6/drivers/net/ixgb.new/ixgb_main.c
diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index 0a0f041..db1089c 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -1822,7 +1822,6 @@
struct pci_dev *pdev = adapter->pdev;
struct ixgb_rx_desc *rx_desc, *next_rxd;
struct ixgb_buffer *buffer_info, *next_buffer, *next2_buffer;
- struct sk_buff *skb, *next_skb;
uint32_t length;
unsigned int i, j;
boolean_t cleaned = FALSE;
@@ -1832,6 +1831,8 @@
buffer_info = &rx_ring->buffer_info[i];
while(rx_desc->status & IXGB_RX_DESC_STATUS_DD) {
+ struct sk_buff *skb, *next_skb;
+ u8 status;
#ifdef CONFIG_IXGB_NAPI
if(*work_done >= work_to_do)
@@ -1839,7 +1840,9 @@
(*work_done)++;
#endif
+ status = rx_desc->status;
skb = buffer_info->skb;
+
prefetch(skb->data);
if(++i == rx_ring->count) i = 0;
@@ -1864,7 +1867,7 @@
length = le16_to_cpu(rx_desc->length);
- if(unlikely(!(rx_desc->status & IXGB_RX_DESC_STATUS_EOP))) {
+ if(unlikely(!(status & IXGB_RX_DESC_STATUS_EOP))) {
/* All receives must fit into a single buffer */
@@ -1872,12 +1875,7 @@
"length<%x>\n", length);
dev_kfree_skb_irq(skb);
- rx_desc->status = 0;
- buffer_info->skb = NULL;
-
- rx_desc = next_rxd;
- buffer_info = next_buffer;
- continue;
+ goto rxdesc_done;
}
if (unlikely(rx_desc->errors
@@ -1886,12 +1884,7 @@
IXGB_RX_DESC_ERRORS_RXE))) {
dev_kfree_skb_irq(skb);
- rx_desc->status = 0;
- buffer_info->skb = NULL;
-
- rx_desc = next_rxd;
- buffer_info = next_buffer;
- continue;
+ goto rxdesc_done;
}
/* Good Receive */
@@ -1902,7 +1895,7 @@
skb->protocol = eth_type_trans(skb, netdev);
#ifdef CONFIG_IXGB_NAPI
- if(adapter->vlgrp && (rx_desc->status & IXGB_RX_DESC_STATUS_VP)) {
+ if(adapter->vlgrp && (status & IXGB_RX_DESC_STATUS_VP)) {
vlan_hwaccel_receive_skb(skb, adapter->vlgrp,
le16_to_cpu(rx_desc->special) &
IXGB_RX_DESC_SPECIAL_VLAN_MASK);
@@ -1910,7 +1903,7 @@
netif_receive_skb(skb);
}
#else /* CONFIG_IXGB_NAPI */
- if(adapter->vlgrp && (rx_desc->status & IXGB_RX_DESC_STATUS_VP)) {
+ if(adapter->vlgrp && (status & IXGB_RX_DESC_STATUS_VP)) {
vlan_hwaccel_rx(skb, adapter->vlgrp,
le16_to_cpu(rx_desc->special) &
IXGB_RX_DESC_SPECIAL_VLAN_MASK);
@@ -1920,9 +1913,12 @@
#endif /* CONFIG_IXGB_NAPI */
netdev->last_rx = jiffies;
+rxdesc_done:
+ /* clean up descriptor, might be written over by hw */
rx_desc->status = 0;
buffer_info->skb = NULL;
+ /* use prefetched values */
rx_desc = next_rxd;
buffer_info = next_buffer;
}