Re: [RFC PATCH v9 00/16] Provide a zero-copy method on KVM virtio-net.

Shirley Ma
2010-09-13T21:35:59Z

On Fri, 2010-09-03 at 13:52 +0300, Michael S. Tsirkin wrote:
> > When binding vhost thread to cpu3, qemu I/O thread to cpu2, macvtap
> zero
> > copy patch can get 9.4Gb/s.
> >
> > TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to
> 192.168.10.74 (192.168.10.74) port 0 AF_INET : cpu bind
> > Recv Send Send Utilization
> Service Demand
> > Socket Socket Message Elapsed Send Recv Send
> Recv
> > Size Size Size Time Throughput local remote local
> remote
> > bytes bytes bytes secs. 10^6bits/s % S % S us/KB
> us/KB
> >
> > 87380 16384 65536 60.00 9408.19 55.69 8.45 0.970
> 0.589
> >
> > Shirley
>
> OTOH CPU utilization is up too.

w/i macvtap zero copy patch, the BW can reach link w/i more cpu usage,
w/o macvtap zero copy patch, the BW can't be up to link speed. To
achieve same BW, CPU utilization is lower when using zero copy.

Shirley