rc.conf(5): comparing kld_list and kldload

[Kyle Evans]

On Mon, Oct 22, 2018 at 9:05 AM Polytropon <freebsd at edvax.de> wrote:
>
> On Mon, 22 Oct 2018 05:26:18 +0100, Graham Perrin wrote:
> > From <https://www.freebsd.org/cgi/man.cgi?query=rc.conf&sektion=5&manpath=FreeBSD>:
> >
> > > …
> > >
> > > kld_list    (str) A list of kernel modules to load right after
> > >             the local disks are mounted.  Loading modules at
> > >             this point in the boot process is much faster than
> > >             doing it via /boot/loader.conf for those modules
> > >             not necessary for mounting local disk.
> > > …
> >
> > Is there ever any benefit to using kldload instead of kld_list?
>
> It is important when you consider the _time_ during system
> startup. Sometimes modules require to be loaded at a certain
> time, that's when you can (or cannot) use kld_list, which is
> the _default_ method of loading kernel modules.
>
> early: via /boot/loader.conf
>
> intermediate: via kld_list in /etc/rc.conf
>
> almost final: via kldload calls in /etc/rc.local
>
> It's also possible for scripts in /usr/local/etc/rc.d/ to
> load kernel modules, and you could even add something to
> /etc/rc itself to achieve "really final" loading (even though
> manual additions to /etc/rc are discouraged for good reasons).
>

It's worth noting that /boot/loader.conf is not an option for drm
modules in head and stable/12, so only the above "intermediate" and
"almost final" options are suitable for testing here.

Thanks,

Kyle Evans