On Sun, Feb 15, 2015 at 3:30 PM, Ding Xiao <ssdxiaoding@xxxxxxxxx> wrote:
I am test virtio-vhost in 10G environment host info cpu E2680@2.7GHz memory 16G network intel 82599BE os centos 7 VM info cpu 4 memory 4G network using virtio vhost os centos 7 I using pktgen to send udp package, the result like follow 64b 230Mb/s 1400b 5.9Gb/s I test the speed in VMware too, the result like follow 64b 700Mb/s 1400 9.3Gb/s I am very surprised why the speed with virtio-vhost is slow so I test to analysis this by using perf tool I found the tun_sendmsg occupancy rate of 35%
It looks like you're using pktgen in guest. Pktgen has known issue with driver that does not have tx completion. See discussion here: https://patchwork.kernel.org/patch/1800711/
So you can't trust pktgen result in this case.
tun_sendmsg using copy_from_user to get the data from VM Perhaps mapping could improve the performance ?
If you enable vhost_net zerocopy, you will see obvious improvements.
or other Another improvement method ?
I suggest that you can use other benchmark tools (or apply the patch in the above link with pktgen).
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