于 2014年11月06日 00:08, Jesse Gross 写道:
On Tue, Nov 4, 2014 at 11:03 PM, FengYu LeiDian
<fengyuleidian0...@gmail.com> wrote:
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%,
Your NIC probably doesn't support offloads (checksum, TSO, etc.) in
the presence of VXLAN.
This is the default features supported by my NIC 82599 both in case1 and
case2.
Features for eth4:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: on
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: on
large-receive-offload: off
rx-vlan-offload: on
tx-vlan-offload: on
ntuple-filters: on
receive-hashing: on
In vxlan scenario in case2:
1. Set eth4 mtu to a larger value to make udp packet not fragmented,
so ufo won't be involved here.
2. enable UDP RSS by:
ethtool -N eth4 rx-flow-hash udp4 sdfn
After setting UDP RSS, udp packets are scaled into multiple queues.
Without UDP RSS, udp packets fall into a single queue. Then the
performance changed from 2Gbps to 2.5Gbps, still large drop
compared with original none vxlan 7.6Gbps scenario.
_______________________________________________
discuss mailing list
discuss@openvswitch.org
http://openvswitch.org/mailman/listinfo/discuss
