vxlan: vxlan dev should inherit lowerdev's gso_max_size
vxlan dev currently ignores lowerdev's gso_max_size, which adversely
affects TSO performance of liquidio if it's the lowerdev. Egress TCP
packets' skb->len often exceed liquidio's advertised gso_max_size. This
may happen on other NIC drivers.
Fix it by assigning lowerdev's gso_max_size to that of vxlan dev. Might as
well do likewise for gso_max_segs.
Single flow TSO throughput of liquidio as lowerdev (using iperf3):
Before the patch: 139 Mbps
After the patch : 8.68 Gbps
Percent increase: 6,144 %
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: Satanand Burla <satananda.burla@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 1e54fb5..714f74f 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2926,6 +2926,11 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
return -EINVAL;
}
+ if (lowerdev) {
+ dev->gso_max_size = lowerdev->gso_max_size;
+ dev->gso_max_segs = lowerdev->gso_max_segs;
+ }
+
if (conf->mtu) {
int max_mtu = ETH_MAX_MTU;