Re: [PATCH net-next 03/21] ethtool, stats: introduce standard XDP statistics

[Saeed Mahameed]

On Wed, 2021-08-04 at 18:43 -0600, David Ahern wrote:
> On 8/4/21 12:27 PM, Saeed Mahameed wrote:
> > 
> > > I just ran some quick tests with my setup and measured about 1.2%
> > > worst
> > 
> > 1.2% is a lot ! what was the test ? what is the change ?
> 
> I did say "quick test ... not exhaustive" and it was definitely
> eyeballing a pps change over a small time window.
> 
> If multiple counters are bumped 20-25 million times a second (e.g.
> XDP
> drop case), how measurable is it? I was just trying to ballpark the
> overhead - 1%, 5%, more? If it is <~ 1% then there is no performance
> argument in which case let's do the right thing for users - export
> via
> existing APIs.

from experience I don't believe it can be more than 1% and yes on
existing APIs !