Re: [gentoo-user] Re: decrapify your kernel config

[Volker Armin Hemmann <volkerarmin@googlemail.com>]

On Mittwoch 18 November 2009, Alan McKinnon wrote:
> On Wednesday 18 November 2009 01:16:04 Stefan G. Weichinger wrote:
> > Volker Armin Hemmann schrieb:
> > > Namespaces - you don't need it? Kick 'em out.
> >
> > hmm, interesting ... ;-)
> >
> > for sure I also want to decrapify my kernel-config ...
> >
> > To disable namespaces I would have to set CONFIG_EMBEDDED=y ... correct?
> >
> > This is rather counterintuitive to me, as my main workstation is far
> > from an embedded or small system (ok, not compared to the
> > 4096-cpu-clusters in http://xkcd.com/619/ , but compared to, for
> > example, my embedded ALIX-PC I use as fw/router/something ...).
> >
> > So you suggest I set CONFIG_EMBEDDED=y and in turn get several new
> > options/defaults to choose and get right or wrong ... ?
> >
> > ;-)
> >
> > I am quite sure to have at least *some* crap in my config as I tend to
> > always do something like
> >
> > zcat /proc/config.gz >> /usr/src/linux-new-shiny-version/.config
> > make oldconfig
> >
> > ....
> >
> > This gives me expected results and a "it boots OK" experience, getting
> > rid of unused crap is another issue, yes.
> >
> > I wonder which EMBEDDED options would help me ...
> 
> Likely none of them.
> 
> The embedded menu is the most counter-intuitive thing in the whole kernel
> config. It does not supply a list of things you may enable, instead it
> activates a menu that allows you to switch stuff OFF that is normally ON.
> 
> The rationale is that embedded devices need to get by on a very slim kernel
> and with some magic trickery they can successfully disable some features
>  that are usually considered perfectly normal for regular desktop use.
> 
> For example: CONFIG_HOTPLUG. It's unthinkable to remove this for a desktop,
> but does your TomTom need it? Does a GPS even have hotplug facilities? How
> about ADSL router/modems?
> 
> To disable namespace, enable embedded, leave everything on, and you will
>  find you can now disable namespaces.
> 

you can disable:
- Enable 16-bit UID system calls 

- Sysctl syscall support
without negative impact on a desktop. Most of it is broken for years anyway.

- Core dumps
 are another feature that most people never use

- Load all symbols for debugging/ksymoops  
and
- Do an extra kallsyms pass
stuff you can deactivate if you don't plan to send crash reports.

- Enable PC-Speaker support
oh hell - away with that one! Who needs beeps anyway?