Re: RFC: [2.6 patch] disallow modular IPv6

[Arnaldo Carvalho de Melo <acme@conectiva.com.br>]

Em Mon, Sep 29, 2003 at 10:02:55AM +0100, David Woodhouse escreveu:
> On Sun, 2003-09-28 at 21:32 -0300, Arnaldo Carvalho de Melo wrote:
> > Em Mon, Sep 29, 2003 at 02:14:39AM +0200, Adrian Bunk escreveu:
> > > On Sun, Sep 28, 2003 at 08:39:10PM -0300, Arnaldo Carvalho de Melo wrote:
> > > What about the following solution (the names and help texts for the
> > > config options might not be optimal, I hope you understand the
> > > intention):
> > > 
> > > config IPV6_SUPPORT
> > > 	bool "IPv6 support"
> > > 
> > > config IPV6_ENABLE
> > > 	tristate "enable IPv6"
> > > 	depends on IPV6_SUPPORT
> > > 
> > > IPV6_SUPPORT changes structs etc. and IPV6_ENABLE is responsible for 
> > > ipv6.o .
> > 
> > Humm, and the idea is? This seems confusing, could you elaborate on why such
> > scheme is a good thing?
> 
> The idea is that you then have ifdefs on CONFIG_IPV6_SUPPORT not on
> CONFIG_IPV6_MODULE.

That part I understood :)
 
> The underlying point being that your static kernel should not change if
> you change an option from 'n' to 'm'.

But that will only happen if CONFIG_IPV6_SUPPORT is always enabled, no?

> It should only affect the kernel image if you change options to/from 'y'.

That is a good goal, yes, so lets remove all the ifdefs around EXPORT_SYMBOL,
etc, i.e.: add bloat for the simple case were I want a minimal kernel.

Humm, so the user will have, in this case, these choices:

1. "I don't want IPV6 at all, not now, not ever":
	CONFIG_IPV6_SUPPORT=N
	CONFIG_IPV6=N  (this is implicit as this depends on
			CONFIG_IPV6_SUPPORT)
	
2. "I think I may well want it the future, who knows? but not now...":
	CONFIG_IPV6_SUPPORT=Y
	CONFIG_IPV6=N
	
3. "Nah, some of the users of this pre-compiled kernel will need it":
	CONFIG_IPV6_SUPPORT=Y
	CONFIG_IPV6=M
	
4. "Yeah, IPV6 is COOL, how can somebody not use this piece of art?":
	CONFIG_IPV6_SUPPORT=Y
	CONFIG_IPV6=Y

Isn't this confusing for the I-wanna-triple-my-kernel-performance-by-compiling-
the-kernel-for-exactly-what-I-have hordes of users?

- Arnaldo