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

["Stefan G. Weichinger" <lists@xunil.at>]

Volker Armin Hemmann schrieb:
> 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?

whoops. I hadn't looked back at that thread for weeks, only found it now.

Thanks for your replies ....