Re: Performance issues with vnet jails + epair + bridge

From: Sad Clouds <cryintothebluesky_at_gmail.com>
Date: Fri, 13 Sep 2024 07:03:56 UTC
I built new kernel with "options RSS" however TCP throughput performance
now decreased from 128 MiB/sec to 106 MiB/sec.

Looks like the problem has shifted from epair to netisr

  PID USERNAME    PRI NICE   SIZE    RES STATE    C   TIME    WCPU COMMAND
   12 root        -56    -     0B   272K CPU3     3   3:45 100.00% intr{swi1: netisr 0}
   11 root        187 ki31     0B    64K RUN      0   9:00  62.41% idle{idle: cpu0}
   11 root        187 ki31     0B    64K CPU2     2   9:36  61.23% idle{idle: cpu2}
   11 root        187 ki31     0B    64K RUN      1   8:24  55.03% idle{idle: cpu1}
    0 root        -64    -     0B   656K -        2   0:50  21.50% kernel{epair_task_2}

Are there any other tricks I can try to distribute the  load over
multiple CPU cores?

I found this document which describes various vnet examples:
https://freebsdfoundation.org/wp-content/uploads/2020/03/Jail-vnet-by-Examples.pdf

The problem is, with Raspberry Pi I cannot add any pcie network cards
with multiple ports or SR-IOV features. I was hoping to use some software
based virtualization device, but if the scalability is this bad, then
I may have to discard vnet completely and configure jails to use the
host network stack.

Thanks.