[ovs-discuss] performance drop 60% when using vxlan tunnel

[FengYu LeiDian]

Hi

Env: redhat 6.4, OpenvSwitch-2.1.2, using native
datapath/linux/openvswitch.ko module

VM1 on host1, VM2 on host2, host1 and host2 are connected by a switch.
both VM enable virtio/vhost when launching VM

case1:
VM -> tap -> ovs-bridge -> eth1

case2:
VM -> tap -> ovs-bridge -> vxlan -> eth1

When using vxlan in case2, iperf performance drop 60%,
Some thoughts on this:
1. using native openvsiwtch.ko module, vxlan src port is randomly
chosen. So hash on the same hw queue is not possible.
2. set eth1 mtu to 9000, same effect, no luck.
3. Tried mater 2.3, same effect
4. set df_default=1 when add vxlan interface to ovs bridge, same effect.

Script:
Most of steps is from INSTALL in ovs tree, and this is how to create
vxlan tunnel and add it to ovs bridge:
ovs-vsctl add-port ovs-br0 vxlan1 -- set interface vxlan1 type=vxlan
options:remote_ip=192.168.5.11 options:key=99 options:dst_port=4789
options:df_default=1


Is there any knobs in vxlan to twick with?
Any tips/suggestions would be welcome.