VNET performance

[Bjoern A. Zeeb]

On 10 Jul 2014, at 20:45 , Clint Armstrong <clint at clintarmstrong.net> wrote:

> What is the expected network performance of a VNET jail for network
> communication between the jail and the host, or between multiple jails? I
> expected it to approach the 10Gbps of the epair device, but I'm not seeing
> that.
> 
> I see between 800 - 1200 Mbps in standard iperf tests both between the host
> bridge interface and the vnet jail inteface. I see the same poor speeds if
> I make 2 vnet jails and put one side of the epair in each and test between
> them.
> 
> Is the overhead of vnet causing this? Is there anything I can do to improve
> this performance.
> 
> I’ve tested and seen similar performance on 10.0-RELEASE and 11.0-CURRENT.

epair has a netisr queuing in between as you cannot call the input routines directly from the output routines.  I was able to get a bit more traffic through by doing pinning games.

I wonder what a vale switch for vnets could achieve.

— 
Bjoern A. Zeeb             "Come on. Learn, goddamn it.", WarGames, 1983