diff options
| author | Zhu Yanjun <yanjun.zhu@oracle.com> | 2017-11-10 21:10:00 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-11-13 10:40:19 +0900 |
| commit | 0d728b844c2dd8dd3875ed304eee43967c5d14f6 (patch) | |
| tree | 37f4a74f34fc52147e5b855c21a1985138c122e0 /drivers/net/ethernet | |
| parent | 6afce196236c353819526a1c41fffb6d660eb2ef (diff) | |
| download | lwn-0d728b844c2dd8dd3875ed304eee43967c5d14f6.tar.gz lwn-0d728b844c2dd8dd3875ed304eee43967c5d14f6.zip | |
forcedeth: remove redudant assignments in xmit
In xmit process, the variables are set many times. In fact,
it is enough for these variables to be set once.
After a long time test, the throughput performance is better
than before.
CC: Srinivas Eeda <srinivas.eeda@oracle.com>
CC: Joe Jin <joe.jin@oracle.com>
CC: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet')
| -rw-r--r-- | drivers/net/ethernet/nvidia/forcedeth.c | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c index 31a943860f32..ac8439ceea10 100644 --- a/drivers/net/ethernet/nvidia/forcedeth.c +++ b/drivers/net/ethernet/nvidia/forcedeth.c @@ -2226,8 +2226,6 @@ static netdev_tx_t nv_start_xmit(struct sk_buff *skb, struct net_device *dev) /* setup the header buffer */ do { - prev_tx = put_tx; - prev_tx_ctx = np->put_tx_ctx; bcnt = (size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : size; np->put_tx_ctx->dma = dma_map_single(&np->pci_dev->dev, skb->data + offset, bcnt, @@ -2262,8 +2260,6 @@ static netdev_tx_t nv_start_xmit(struct sk_buff *skb, struct net_device *dev) offset = 0; do { - prev_tx = put_tx; - prev_tx_ctx = np->put_tx_ctx; if (!start_tx_ctx) start_tx_ctx = tmp_tx_ctx = np->put_tx_ctx; @@ -2304,6 +2300,16 @@ static netdev_tx_t nv_start_xmit(struct sk_buff *skb, struct net_device *dev) } while (frag_size); } + if (unlikely(put_tx == np->first_tx.orig)) + prev_tx = np->last_tx.orig; + else + prev_tx = put_tx - 1; + + if (unlikely(np->put_tx_ctx == np->first_tx_ctx)) + prev_tx_ctx = np->last_tx_ctx; + else + prev_tx_ctx = np->put_tx_ctx - 1; + /* set last fragment flag */ prev_tx->flaglen |= cpu_to_le32(tx_flags_extra); @@ -2377,8 +2383,6 @@ static netdev_tx_t nv_start_xmit_optimized(struct sk_buff *skb, /* setup the header buffer */ do { - prev_tx = put_tx; - prev_tx_ctx = np->put_tx_ctx; bcnt = (size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : size; np->put_tx_ctx->dma = dma_map_single(&np->pci_dev->dev, skb->data + offset, bcnt, @@ -2414,8 +2418,6 @@ static netdev_tx_t nv_start_xmit_optimized(struct sk_buff *skb, offset = 0; do { - prev_tx = put_tx; - prev_tx_ctx = np->put_tx_ctx; bcnt = (frag_size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : frag_size; if (!start_tx_ctx) start_tx_ctx = tmp_tx_ctx = np->put_tx_ctx; @@ -2456,6 +2458,16 @@ static netdev_tx_t nv_start_xmit_optimized(struct sk_buff *skb, } while (frag_size); } + if (unlikely(put_tx == np->first_tx.ex)) + prev_tx = np->last_tx.ex; + else + prev_tx = put_tx - 1; + + if (unlikely(np->put_tx_ctx == np->first_tx_ctx)) + prev_tx_ctx = np->last_tx_ctx; + else + prev_tx_ctx = np->put_tx_ctx - 1; + /* set last fragment flag */ prev_tx->flaglen |= cpu_to_le32(NV_TX2_LASTPACKET); |