On Tue, Apr 02, 2019 at 04:19:25AM +0000, Alex Bennée wrote:
>
> My main interest is how it stacks up against:
>
> --device virtio-net-pci and I guess the vhost equivalent
>
Hi Alex,
I added TCP tests on virtio-net and I did also a test with TCP_NODELAY,
just to be fair, because VSOCK doesn't implement something like this
(maybe could be an improvement to add for maximizing the throughput).
I set the MTU to the maximum allowed (65520).
I also redo the VSOCK tests. There are some differences because now I'm
using tuned to have fewer fluctuations and I removed batching in VSOCK
optimization because it is not ready to be published.
VSOCK TCP + virtio-net + vhost
host -> guest [Gbps] host -> guest [Gbps]
pkt_size before opt. optimized TCP_NODELAY
64 0.060 0.096 0.16 0.15
256 0.22 0.36 0.32 0.57
512 0.42 0.74 1.2 1.2
1K 0.7 1.5 2.1 2.1
2K 1.5 2.9 3.5 3.4
4K 2.5 5.3 5.5 5.3
8K 3.9 8.8 8.0 7.9
16K 6.6 12.8 9.8 10.2
32K 9.9 18.1 11.8 10.7
64K 13.5 21.4 11.4 11.3
128K 17.9 23.6 11.2 11.0
256K 18.0 24.4 11.1 11.0
512K 18.4 25.3 10.1 10.7
Note: Maybe I have something miss configured because TCP on virtio-net
doesn't exceed 11 Gbps.
VSOCK TCP + virtio-net + vhost
guest -> host [Gbps] guest -> host [Gbps]
pkt_size before opt. optimized TCP_NODELAY
64 0.088 0.101 0.24 0.24
256 0.35 0.41 0.36 1.03
512 0.70 0.73 0.69 1.6
1K 1.1 1.3 1.1 3.0
2K 2.4 2.6 2.1 5.5
4K 4.3 4.5 3.8 8.8
8K 7.3 7.6 6.6 20.0
16K 9.2 11.1 12.3 29.4
32K 8.3 18.1 19.3 28.2
64K 8.3 25.4 20.6 28.7
128K 7.2 26.7 23.1 27.9
256K 7.7 24.9 28.5 29.4
512K 7.7 25.0 28.3 29.3
virtio-net is well optimized than VSOCK, but we are near :). Maybe we
will use virtio-net as a transport for VSOCK, in order to avoid duplicate
optimizations.
How to reproduce TCP tests:
host$ ip link set dev br0 mtu 65520
host$ ip link set dev tap0 mtu 65520
host$ qemu-system-x86_64 ... \
-netdev tap,id=net0,vhost=on,ifname=tap0,script=no,downscript=no \
-device virtio-net-pci,netdev=net0
guest$ ip link set dev eth0 mtu 65520
guest$ iperf3 -s
host$ iperf3 -c ${VM_IP} -N -l ${pkt_size} # host -> guest
host$ iperf3 -c ${VM_IP} -N -l ${pkt_size} -R # guest -> host
Cheers,
Stefano
