cxgb4/cxgb4vf: Fixes regression in perf when tx vlan offload is disabled

The commit 637d3e9973 ("cxgb4: Discard the packet if the length is
greater than mtu") introduced a regression in the VLAN interface
performance when Tx VLAN offload is disabled.

Check if skb is tagged, regardless of whether it is hardware accelerated
or not. Presently we were checking only for hardware acclereated one,
which caused performance to drop to ~0.17Mbps on a 10GbE adapter for
VLAN interface, when tx vlan offload is turned off using ethtool.
The ethernet head length calculation was going wrong in this case, and
driver ended up dropping packets.

Fixes: 637d3e9973 ("cxgb4: Discard the packet if the length is greater than mtu")
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hariprasad Shenai 2016-07-28 13:28:57 +05:30 committed by David S. Miller
parent b2df430b52
commit 8d09e6b8b9
2 changed files with 2 additions and 2 deletions

View File

@ -1192,7 +1192,7 @@ out_free: dev_kfree_skb_any(skb);
/* Discard the packet if the length is greater than mtu */ /* Discard the packet if the length is greater than mtu */
max_pkt_len = ETH_HLEN + dev->mtu; max_pkt_len = ETH_HLEN + dev->mtu;
if (skb_vlan_tag_present(skb)) if (skb_vlan_tagged(skb))
max_pkt_len += VLAN_HLEN; max_pkt_len += VLAN_HLEN;
if (!skb_shinfo(skb)->gso_size && (unlikely(skb->len > max_pkt_len))) if (!skb_shinfo(skb)->gso_size && (unlikely(skb->len > max_pkt_len)))
goto out_free; goto out_free;

View File

@ -1188,7 +1188,7 @@ int t4vf_eth_xmit(struct sk_buff *skb, struct net_device *dev)
/* Discard the packet if the length is greater than mtu */ /* Discard the packet if the length is greater than mtu */
max_pkt_len = ETH_HLEN + dev->mtu; max_pkt_len = ETH_HLEN + dev->mtu;
if (skb_vlan_tag_present(skb)) if (skb_vlan_tagged(skb))
max_pkt_len += VLAN_HLEN; max_pkt_len += VLAN_HLEN;
if (!skb_shinfo(skb)->gso_size && (unlikely(skb->len > max_pkt_len))) if (!skb_shinfo(skb)->gso_size && (unlikely(skb->len > max_pkt_len)))
goto out_free; goto out_free;