forcedeth: optimize the xmit/rx with unlikely
In the xmit/rx fastpath, the function dma_map_single rarely fails.
Therefore, add an unlikely() optimization to this error check
conditional.
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
index b605b94..a235e88 100644
--- a/drivers/net/ethernet/nvidia/forcedeth.c
+++ b/drivers/net/ethernet/nvidia/forcedeth.c
@@ -1817,8 +1817,8 @@
skb->data,
skb_tailroom(skb),
DMA_FROM_DEVICE);
- if (dma_mapping_error(&np->pci_dev->dev,
- np->put_rx_ctx->dma)) {
+ if (unlikely(dma_mapping_error(&np->pci_dev->dev,
+ np->put_rx_ctx->dma))) {
kfree_skb(skb);
goto packet_dropped;
}
@@ -1858,8 +1858,8 @@
skb->data,
skb_tailroom(skb),
DMA_FROM_DEVICE);
- if (dma_mapping_error(&np->pci_dev->dev,
- np->put_rx_ctx->dma)) {
+ if (unlikely(dma_mapping_error(&np->pci_dev->dev,
+ np->put_rx_ctx->dma))) {
kfree_skb(skb);
goto packet_dropped;
}
@@ -2227,8 +2227,8 @@
np->put_tx_ctx->dma = dma_map_single(&np->pci_dev->dev,
skb->data + offset, bcnt,
DMA_TO_DEVICE);
- if (dma_mapping_error(&np->pci_dev->dev,
- np->put_tx_ctx->dma)) {
+ if (unlikely(dma_mapping_error(&np->pci_dev->dev,
+ np->put_tx_ctx->dma))) {
/* on DMA mapping error - drop the packet */
dev_kfree_skb_any(skb);
u64_stats_update_begin(&np->swstats_tx_syncp);
@@ -2268,7 +2268,8 @@
frag, offset,
bcnt,
DMA_TO_DEVICE);
- if (dma_mapping_error(&np->pci_dev->dev, np->put_tx_ctx->dma)) {
+ if (unlikely(dma_mapping_error(&np->pci_dev->dev,
+ np->put_tx_ctx->dma))) {
/* Unwind the mapped fragments */
do {
@@ -2377,8 +2378,8 @@
np->put_tx_ctx->dma = dma_map_single(&np->pci_dev->dev,
skb->data + offset, bcnt,
DMA_TO_DEVICE);
- if (dma_mapping_error(&np->pci_dev->dev,
- np->put_tx_ctx->dma)) {
+ if (unlikely(dma_mapping_error(&np->pci_dev->dev,
+ np->put_tx_ctx->dma))) {
/* on DMA mapping error - drop the packet */
dev_kfree_skb_any(skb);
u64_stats_update_begin(&np->swstats_tx_syncp);
@@ -2419,7 +2420,8 @@
bcnt,
DMA_TO_DEVICE);
- if (dma_mapping_error(&np->pci_dev->dev, np->put_tx_ctx->dma)) {
+ if (unlikely(dma_mapping_error(&np->pci_dev->dev,
+ np->put_tx_ctx->dma))) {
/* Unwind the mapped fragments */
do {
@@ -5075,8 +5077,8 @@
test_dma_addr = dma_map_single(&np->pci_dev->dev, tx_skb->data,
skb_tailroom(tx_skb),
DMA_FROM_DEVICE);
- if (dma_mapping_error(&np->pci_dev->dev,
- test_dma_addr)) {
+ if (unlikely(dma_mapping_error(&np->pci_dev->dev,
+ test_dma_addr))) {
dev_kfree_skb_any(tx_skb);
goto out;
}