Re: CFT: lem(4), em(4) e1000 Ethernet TSO testing

Committed as https://cgit.freebsd.org/src/commit/?id=f1b5488f7bba7f25a57750f87cbcbccbd5b9d16b

On Tue, Jul 25, 2023 at 7:38 PM Kevin Bowling <kevin.bowling@kev009.com> wrote:
>
> Hi,
>
> I have been working through various bugs and have come to a point
> where TSO is working on systems I have available for testing.
>
> This results in higher throughput on resource constrained systems, and
> less CPU/power usage on unconstrained systems.
>
> As of this mail, you will need to manually apply
> https://reviews.freebsd.org/D41170 on top of main to use TSO6 on
> em(4).
>
> I plan to enable TSO by default for lem(4) and em(4) during the
> FreeBSD 14 release cycle, so I would appreciate testing to address any
> remaining issues.  Below, a list of chipsets that will be exempt due
> to known issues.
>
> lem(4) exclusions:
> * <82544 (although it does seem ok to manually enable for emulations
> in qemu, virtualbox, etc)
> * 82547
>
> em(4) exclusions.. These chips have a stability workaround for high
> throughput with rapid link-flap applied that results in the TSO engine
> not being able to run at line speed.  Thus, TSO would not be enabled
> by default here:
> * Intel(R) I219-LM and I219-V
> * Intel(R) I219-LM and I219-V (2)
> * Intel(R) I219-LM and I219-V (3)
> * Intel(R) I219-LM and I219-V (4)
> * Intel(R) I219-LM and I219-V (5)
>
> Regards,
> Kevin Bowling