Re: CVS commit: src/sys

[Antti Kantee <pooka%cs.hut.fi@localhost>]

On Tue Jan 20 2009 at 09:58:30 +0000, David Holland wrote:
> I think pretending that COMPAT_* can always be built strictly as a
> module is a losing proposition. But then, you probably already knew
> I'd say that. :-)

"oh no, someone is wrong on the internet" ;)

Seriously though, I almost agree with you, but I would propose to drop
compat for cases which can't be accomodated with reasonable difficulty.

Out of our examples, it is not unreasonable for kernfs to support
dynamically registering nodes.  This even has nothing per se to do
with compat.

What would break if the routing socket wouldn't support old message types?
If it's just a handful of system utilities, I don't think upgrading the
whole system is an unreasonable requirement.  It's not like the compat
is perfect even now, though we might want to claim it to be.

If the whole world breaks, well, we probably should compile compat in
all the time to prevent people from shooting theirselves in the foot.

(yes, I value compat.  I'm currently running 5.0_BETA kernel on a
4.99.30'ish userland.  But maybe it's a better idea to support rollback
of userland utilities than try to pile a ton of cornercase compat into
the kernel)