Re: [Ksummit-discuss] RFC: Kernel tinification - kernel config reduction

[Christoph Lameter <cl@gentwo.org>]

On Wed, 13 Aug 2014, Bird, Tim wrote:

> I propose that we remove or hide a lot of the configuration options related
> to size, and instead focus on size profiles. When someone wants to build a
> minimal Linux system, they don't really want to manually trim down every
> Linux sub-system.  The more common development case is that they want

Yes exactly.

> a fully minimal Linux system, except for one or two areas where they want
> some flexibility in features.  I propose that we tie most of the options that
> are currently in the kernel for size reasons to a single or a few meta-options:
> e.g. CONFIG_SMALL, CONFIG_TINY, CONFIG_RIDICULOUS.  These
> different meta-config options can get better testing, and this will help curb
> the proliferation of size-related config options (and the resulting test
> combination explosion for those individual options.)

I'd be interested to configure minimally sized systems in order to
increase performance. The cache footprint determines performance these
days so a tinyfication project will have performance implications as well
and has the potential to significantly speed up key kernel functionality.

> Optimally it would be nice to have the ability to configure a small system, and
> then "back off" of the tiny config in a particular area (say networking).
> I believe this would yield a much more tractable system for building small
> systems with Linux, than the current situation.

That could be useful also to come up with high performant kernels for
special functionality. Come up with a tiny config and then add config
options to enable only what is needed.

Reminds me of what Gentoo is doing

> I'd like to discuss implementation ideas for this in the hallway track at KS.
>
> Thoughts?

Get a room instead of the hallway?