Re: [PATCH v2 net-next 21/26] ice: add XDP and XSK generic per-channel statistics

[Jakub Kicinski]

On Fri, 26 Nov 2021 19:47:17 +0100 Toke Høiland-Jørgensen wrote:
> > Fair. In all honesty I said that hoping to push for a more flexible
> > approach hidden entirely in BPF, and not involving driver changes.
> > Assuming the XDP program has more fine grained stats we should be able
> > to extract those instead of double-counting. Hence my vague "let's work
> > with apps" comment.
> >
> > For example to a person familiar with the workload it'd be useful to
> > know if program returned XDP_DROP because of configured policy or
> > failure to parse a packet. I don't think that sort distinction is
> > achievable at the level of standard stats.
> >
> > The information required by the admin is higher level. As you say the
> > primary concern there is "how many packets did XDP eat".  
> 
> Right, sure, I am also totally fine with having only a somewhat
> restricted subset of stats available at the interface level and make
> everything else be BPF-based. I'm hoping we can converge of a common
> understanding of what this "minimal set" should be :)
> 
> > Speaking of which, one thing that badly needs clarification is our
> > expectation around XDP packets getting counted towards the interface
> > stats.  
> 
> Agreed. My immediate thought is that "XDP packets are interface packets"
> but that is certainly not what we do today, so not sure if changing it
> at this point would break things?

I'd vote for taking the risk and trying to align all the drivers.