Ubuntu kernel builds

[Alan McKinnon]

On Wednesday 15 March 2006 14:59, R Kimber wrote:
> On Wed, 15 Mar 2006 13:49:58 +0200
>
> Alan McKinnon <alan at linuxholdings.co.za> wrote:
> > On Wednesday 15 March 2006 12:26, R Kimber wrote:
> > > I notice from the logs that the kernel I'm running seems to
> > > have been built using gcc version 3.4.5 20050809 (prerelease).
> > >
> > > Shouldn't kernels be built with a stable version of gcc as
> > > approved by the kernel developers?
> >
> > There isn't a "should" aspect to it - you can compile the kernel
> > with any compiler you like.
>
> But is it wise to be using a prerelease version of gcc?
>
> How confident can one be that you get an equally stable kernel
> using "any compiler you like"?

Obviously, you can't be confident at all. But I don't think this is a 
binary problem with a yes/no answer, it's highly modified by 
viewpoint, starting with "define 'stable'". Debian has one 
definition, but many would argue that that equates to 'obsolete' 
elsewhere.

The deployment role also factors in, I'd be happy with that kernel on 
a machine my mother will use to send email, not so on a 
mission-critical server (for which I'd probably use debian-stable). 
And I'd go ballistic if it were used on the Space Shuttle.

What we don't know is the parameters and limits the kernel packager 
works under, or what the official policy is. Until we know that, we 
can speculate but not be sure.

> > Your question is probably related to the README in the kernel
> > sources, where the developers are basically saying:
> >
> > "We recommend you use 2.95.3 because we have lots of history on
> > that version. If you use something else and have a problem we
> > won't know if it's because of a different compiler or a code bug,
> > so don't expect us to fall over ourselves to help you out."
> >
> > In practice compiling a kernel with 3.x.y is quite safe
>
> Actually, I wasn't specifically addressing that issue.  I was
> concerned about the stability of the kernel built with a non-stable
> version of gcc.

As a matter of policy it's probably a good idea to dictate that 
kernels must be built with version that the GCC coders consider 
stable. Especially as the rest of the distro is compiled with a 
different compiler anyway.

> However, since you raised it, history has obviously taught the
> developers something that has lead them to think that not all gccs
> are equal, as it were.

With a healthy dose of the "yes, this is more work for you and no, we 
don't care" attitude thrown in for good measure...

-- 
Alan McKinnon
alan at linuxholdings dot co dot za
+27 82, double three seven, one nine three five