Re: [PATCH V3 3/7] net/mlx5: add new devargs to control probe optimization

[Thomas Monjalon <thomas@monjalon.net>]

29/10/2024 17:20, Stephen Hemminger:
> On Tue, 29 Oct 2024 15:42:52 +0200
> "Minggang Li(Gavin)" <gavinl@nvidia.com> wrote:
> 
> > From: Rongwei Liu <rongweil@nvidia.com>
> > 
> > Add a new devarg probe_opt_en to control probe optimization
> > in PMD.
> > 
> > By default, the value is 0 and no behavior changed.
> > 
> > Signed-off-by: Rongwei Liu <rongweil@nvidia.com>
> > Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> 
> Once again, every option you introduce expands the test space by 2X.
> "Do or Do not. There is no try"
> Either it works all the time or it is a bad idea.

I fully agree.
We should not merge this series before providing a good answer,
or making it automatic.

One more thing: a commit log should always explain "why".
Here it should say why it is not automatic.
Is there a good reason to disable this feature?

> Sorry if I sound like a broken record, the project I used to work on
> had the same kind of "always add an option" policy. But every time
> an option was changed, there was a 50/50 chance that it was broken because
> that combination of options had not been tested since originally added
> and was non functional due to bit rot.