On Mon, Dec 13, 2010 at 03:27:06PM +0000, Stefan Hajnoczi wrote: > On Mon, Dec 13, 2010 at 1:36 PM, Michael S. Tsirkin <m...@redhat.com> wrote: > > On Mon, Dec 13, 2010 at 03:35:38PM +0200, Michael S. Tsirkin wrote: > >> On Mon, Dec 13, 2010 at 01:11:27PM +0000, Stefan Hajnoczi wrote: > >> > Fresh results: > >> > > >> > 192.168.0.1 - host (runs netperf) > >> > 192.168.0.2 - guest (runs netserver) > >> > > >> > host$ src/netperf -H 192.168.0.2 -- -m 200 > >> > > >> > ioeventfd=on > >> > TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.0.2 > >> > (192.168.0.2) port 0 AF_INET > >> > Recv Send Send > >> > Socket Socket Message Elapsed > >> > Size Size Size Time Throughput > >> > bytes bytes bytes secs. 10^6bits/sec > >> > 87380 16384 200 10.00 1759.25 > >> > > >> > ioeventfd=off > >> > TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.0.2 > >> > (192.168.0.2) port 0 AF_INET > >> > Recv Send Send > >> > Socket Socket Message Elapsed > >> > Size Size Size Time Throughput > >> > bytes bytes bytes secs. 10^6bits/sec > >> > > >> > 87380 16384 200 10.00 1757.15 > >> > > >> > The results vary approx +/- 3% between runs. > >> > > >> > Invocation: > >> > $ x86_64-softmmu/qemu-system-x86_64 -m 4096 -enable-kvm -netdev > >> > type=tap,id=net0,ifname=tap0,script=no,downscript=no -device > >> > virtio-net-pci,netdev=net0,ioeventfd=on|off -vnc :0 -drive > >> > if=virtio,cache=none,file=$HOME/rhel6-autobench-raw.img > >> > > >> > I am running qemu.git with v5 patches, based off > >> > 36888c6335422f07bbc50bf3443a39f24b90c7c6. > >> > > >> > Host: > >> > 1 Quad-Core AMD Opteron(tm) Processor 2350 @ 2 GHz > >> > 8 GB RAM > >> > RHEL 6 host > >> > > >> > Next I will try the patches on latest qemu-kvm.git > >> > > >> > Stefan > >> > >> One interesting thing is that I put virtio-net earlier on > >> command line. > > > > Sorry I mean I put it after disk, you put it before. > > I can't find a measurable difference when swapping -drive and -netdev. > > Can you run the same test with vhost? I assume it still outperforms > userspace virtio for small message sizes? I'm interested because that > also uses ioeventfd.
Seems to work same as ioeventfd. > I am wondering if the iothread differences between qemu.git and > qemu-kvm.git can explain the performance results we see. In > particular, qemu.git produces the same (high) throughput whether > ioeventfd is on or off. > > Stefan