Re: Performance issues with vnet jails + epair + bridge

From: Sad Clouds <cryintothebluesky_at_gmail.com>
Date: Fri, 13 Sep 2024 14:54:39 UTC
On Fri, 13 Sep 2024 08:08:02 -0400
Mark Saad <nonesuch@longcount.org> wrote:

> Sad
>    Can you go back a bit you mentioned there is a RPi in the mix ? Some of the raspberries have their nic usb attached under the covers . Which will kill the total speed of things. 
>  
> Can you cobble together a diagram of what you have on either end ?

Hello, I'm not sending data across the network, only between the host
and the jails. I'm trying to evaluate how FreeBSD handles TCP data
locally within a single host.

I understand that vnet jails will have more overhead, compared to a
shared TCP/IP stack via localhost. So I'm trying to measure it and see
where the bottlenecks are.

The Raspberry Pi 4 host has a single vnet jail, exchanging data with
the host via epair(4) and if_bridge(4) interfaces. I don't really know
what topology FreeBSD is using to represent all this so can't draw any
diagrams, but I think all data flows through the kernel internally and
never leaves the physical network interface.