Re: [LTP] [PATCH] ioctl_pidfd02-06: Add CONFIG_USER_NS and CONFIG_PID_NS to needs_kconfigs

Petr Vorel
2026-01-28T07:25:12Z

...
> > > > Because that was my question - really always prefer kconfig even there is a
> > > > simple runtime solution? I'd like to have some "rule" like conclusion we can
> > > > point during review.

> > > I think that from a long term view this is going to be simpler solution
> > > than having many different types of checks. The less diverse these
> > > checks are the easier they are to review and maintain. Hence I lean
> > > towards kernel config checks even though they are slower (mostly
> > > unmeasurable on today's harware) than the alternatives.

> > I think I lean opposite way, and rather have a check for right
> > environment to support the test.
> > You can have feature X enabled in kernel config, but still disabled
> > later at boot/runtime
> > (e.g. max_user_namespaces=0), or a module simply not being loaded.

> +1, all "tristate" configured as module might be missing. (openSUSE JeOS suffers
> with this when minimal kernel is installed).

> But "bool" are safe unless depend on "tristate" configured as module (not the
> case of CONFIG_USER_NS).

> Kind regards,
> Petr

OK, it's a bool, let's merge it.
I'm sorry to block it with a long discussion, but IMHO it was useful to bring
some conclusion (I'm going to send a patch for rules).

Reviewed-by: Petr Vorel <pvorel@suse.cz>

Kind regards,
Petr