The vlan_features was zero which prevents vlan GSO packets to be transmitted to userspace. This is suboptimal so enable this by initialize vlan_features for tuntap.
Netperf shows better performance of guest receiving since vlan TSO works for tuntap: before: netperf -H 192.168.5.4 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.5.4 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.01 2786.67 after: netperf -H 192.168.5.4 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.5.4 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 10.00 8085.49 Signed-off-by: Jason Wang <[email protected]> --- drivers/net/tun.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 29538e6..316c759 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1656,6 +1656,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | TUN_USER_FEATURES; dev->features = dev->hw_features; + dev->vlan_features = dev->features; INIT_LIST_HEAD(&tun->disabled); err = tun_attach(tun, file); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
