Re: [PATCH 0/9][RFC] KVM virtio_net performance

Mark McLoughlin
2008-07-24T16:54:07Z

Hey,
One all all-important thing I forgot to include was a comparison with
lguest :-)

netperf, 10x20s runs (Gb/s) | guest->host | host->guest
-----------------------------+----------------------------+---------------------------
KVM | 4.230/ 4.619/ 4.780/ 0.155 | 8.140/ 8.578/ 8.770/ 0.162
lguest | 5.700/ 5.926/ 6.150/ 0.132 | 8.680/ 9.073/ 9.320/ 0.205

ping -f -c 100000 (ms) | guest->host | host->guest
-----------------------------+----------------------------+---------------------------
KVM | 0.199/ 0.326/ 7.698/ 0.744 | 0.199/ 0.245/ 0.402/ 0.022
lguest | 0.022/ 0.055/ 0.467/ 0.019 | 0.019/ 0.046/89.249/ 0.448

So, puppies gets you an extra 1.3Gb/s guest->host, .5Gb/s host->guest
and much better latency.

Actually, I guess the main reason for the latency difference is that
when lguest gets notified on the tx ring, it immediately sends whatever
is available and then starts a timer. KVM doesn't send anything until
it's tx timer fires or the ring is full.

Cheers,
Mark.