Re: [MiNT] New kernel features

[Tamminen Eero <t150315@students.cc.tut.fi>]

> > Ob-trivia:
> > 
> > For the ones not following linux kernel mailing list, linux is moving
> > backwards here ;-).  They've added a 'capability system' where you can
> > disable certain capabilities such as module loading (usually at boot,
> > for security reasons, so that they can't enabled again without reboot).
> 
> Interesting.  I didn't know that.
> 
> > >From my experiencies with linux I'd say that plain text /kern is so
> > useful, that I would run it with 4MB ST too (with it you can eg
> > drop quite a lot of stuff from boot floppies ;-)).

In general, it provides lots of info you might need in a hurry, but
have forgotten to acquire a program for which would get it from binary
format data.

> Aaaaaarrrgh, why didn't you send this mail to the mailing list? ;-)

Oh, sorry :).  This goes to mailing list.


> > Can user also change the kernel values with it like on linux?
> > An *extremely* useful feature is an ability to add filedescriptors on
> > the fly when your WWW-server runs out of them in the middle of the
> > workday so that you can't just reboot it (after kernel recompile and
> > installation).  (note: you can only _add_ process/total fds)
> 
> The /kern fs is currently read-only.  Not for philosophical reasons but
> merely lazyness and lack of time.  I focussed on those features that
> will aid me in porting the SysVinit to MiNT.
> 
> BTW, I haven't understood what you described there ... Is it possible to
> replace the running kernel under Linux???

<humorous>
If you mean about what some unmentioned person complained about in sfnet
news group ie. 'binary patching' linux by catting new kernel image into
/proc/kmem, no, that doesn't work (the person claimed he had succeeded
in it earlier and that this feature had been broken...).
</humorous>

Several of the linux kernel parameters can be adjusted on the fly
through proc-fs.  Reasons range from resource/load adjustments to
security.  Things that can be configured are network options (eg
firewalling), process specific and total number of open FDs etc.,
'capabilities' and so on.  Most of these are such that you can
only affect them 'in one direction' ie only disable OR enable
stuff or allocated it more.

You might also check out:  http://linuxperf.nl.linux.org/

Besides a few notes about linux kernel options finetuning, it
has some info on finetuning the performance of several widely
used unix programs (such as apache).


	- Eero