Re: Requirement of make oldconfig [was: Re: [kbuild-devel] Re: CML2 1.3.1, aka ...]

[Horst von Brand <vonbrand@inf.utfsm.cl>]

Alan Cox <alan@lxorguk.ukuu.org.uk> said:
> In-Reply-To: <200105031232.f43CW7aA009990@pincoya.inf.utfsm.cl> from "Horst von
>      *** Brand" at May 03, 2001 08:32:07 AM
> > > No, we're just asking you to make the CML2 parser more tolerant of old
> > > and possibly broken configs.

> > It is _much_ easier on everybody involved to just bail out and ask the
> > user (once!) to rebuild the configuration from scratch starting from
> > the defaults.

> No. Every new kernel changes the constraints so every new kernel you have
> to reconfigure from scratch. That also makes it very hard to be sure you got
> the results right.

Really? I've mostly seen symbols added, very rarely did I see constraints
changed. But that might be just my narrow view on the matter...

> oldconfig has a simple algorithm that works well for current cases
> 
> Start at the top of the symbols in file order. If a symbol is new ask the
> user. If a symbol is now violating a constraint it gets set according to 
> existing constraints if not it gets set to its old value.

I understand that to mean: "If it is new and (at least somewhat)
unconstrained, ask the user.  If fully constrained, take that value
unconditionally." This is a _very_ different case from a broken
configuration as a starting point, in which constraints are violated with
the values as set.

Hell, I had to rebuild my .config files from scratch a few times already
because of wild changes in the hardware on which the resulting kernels
would have to run, its not _that_ big a deal to have to perhaps have to do
it once each time a new stable kernel series starts or so.

People, remember that doing certain things in software is just not worth
the effort.
-- 
Dr. Horst H. von Brand                       mailto:vonbrand@inf.utfsm.cl
Departamento de Informatica                     Fono: +56 32 654431
Universidad Tecnica Federico Santa Maria              +56 32 654239
Casilla 110-V, Valparaiso, Chile                Fax:  +56 32 797513