Re: [PATCH net-next v1 2/3] net: dsa: ar9331: add support for pause stats

From: Andrew Lunn
Date: Tue Jun 28 2022 - 03:23:19 EST


> Yeah, the corrections are always iffy. I understand the doubts, and we
> can probably leave things "under-specified" until someone with a strong
> preference comes along. But I hope that the virt example makes it clear
> that neither of the choices is better (SR-IOV NICs would have to start
> adding the pause if we declare rtnl stats as inclusive).
>
> I can see advantages to both counting (they are packets) and not
> counting those frames (Linux doesn't see them, they get "invented"
> by HW).
>
> Stats are hard.

I doubt we can define it either way. I once submitted a patch for one
driver to make it ignore CRC bytes. It then gave the exact same counts
as another hardware i was using, making the testing i was doing
simpler.

The patch got rejected simply because we have both, with CRC and
without CRC, neither is correct, neither is wrong.

So i would keep it KISS, pause frames can be included, but i would not
go to extra effort to include them, or to exclude them.

Andrew