Re: kbuild 2.5 is ready for inclusion in the 2.5 kernel

Kai Germaschewski
2002-05-02T15:41:05Z

On Thu, 2 May 2002, David Woodhouse wrote:

> > I would like to object here. Getting dependencies right for
> > modversions is very much possible in principle, after all modversions
> > are generated in a deterministic process. (It's also possible in
> > practise, though it's quite a bit of work).
>
> To what are you objecting? You aren't disagreeing with Keith here. He
> merely said that there's no chance of him working on modversions until
> the newer build system that's sane w.r.t. dependencies is incorporated.

Well Keith's statement (as I read it) is: modversions are broken, I don't
support them. My statement is: modversions work 95% of the time, why throw
them out?

That doesn't mean the could be replaced by something which works more than
95% of the time later (though 100% will be impossible to achieve anyway
IMO).

> > Modversions is really essential for distributions, where it's badly
> > needed to keep users from causing hard to track down crashes by
> > inserting self-compiled or obtained from whereever else modules into a
> > kernel which was compiled with a different config.
>
> Distributions are unlikely to be shipping 2.5 kernels. As long as
> modversions can be reimplemented properly by the time 2.6 is released,
> what's the harm in disabling it for a while?
>
> It's hard enough to keep kbuild-2.5 up to date with recent kernels as it
> is; let's not keep moving the goalposts by adding new requirements for the
> initial adoption -- once it's in and the makefiles are maintaining
> themselves, we can concentrate on reimplementing the niche features.

I merely disagree with the way how things are done here. Al Viro doesn't
go like: here's a new VFS, everything is handled differently now - oh, and
for the time being symlinks don't work, I'll fix that until 2.6 (I know
this is a a bit extreme, but you get the point).

If Keith went like fixing issues one at a time, he wouldn't have that huge
patch now, which replaces everything and is hard to keep up-to-date.
There's a lot of orthogonal issues with kbuild which can be solved one at
a time, e.g. correct dependency generation, cleaning up Makefiles (like
getting rid of the explicit list-multi link rules), spurious rebuilds,
building built-in and modular objects in one pass, non-recursive make, ...

My understanding is that the Linux way would have been the latter, going
one step at a time, as Al Viro demonstrates perfectly with the VFS layer.

This way it would also have been possible to select which features are
considered worthwhile and which aren't - not "you have to take it all or
nothing"

Anyway, just my opinion, and yes, I'm admittedly preoccupied.

--Kai