Re: kms in defconfig

[Ingo Molnar <mingo@elte.hu>]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> On Tue, 28 Apr 2009, Ingo Molnar wrote:
> 
> > 
> > * Linus Torvalds <torvalds@linux-foundation.org> wrote:
> > 
> > > So yes, it would be good to automate it:
> > > 
> > > > If a tool was available to detect the hardware and create a 
> > > > config tailored for the box, this use for a default config would 
> > > > go away
> > > 
> > > Yeah, I've wished for that.
> > 
> > Steve (Cc:-ed) submitted such a script last year IIRC. It wasnt 
> > particularly complex.
> 
> I've submitted the script a few times to LKML but it is not 
> exactly what people want, but is quite useful in the mean time.
> 
> What people want is a script that will analyze their system 
> devices and enable all the configs that will support them.
> 
> My script requires that you have booted the kernel (or similar 
> kernel with the same config options and modules). It then runs 
> lsmod, and searches for the options that enable those modules. It 
> then reads the current .config file and prints out a new config 
> that disables all module configs that are not used to enable the 
> modules found with lsmod.
> 
> Here's the code (perl script):
> 
> http://rostedt.homelinux.com/code/streamline_config.pl
> 
> The instructions on how to use it are at the top of the file.
> 
> This script has brought down my full kernel compile times with 
> distcc from 50 minutes to under 10.

Looks rather useful IMHO.

I use the following magic incantation in cfs-debug-info.sh to get to 
the distro config automatically:

 KREL=`uname -r | sed 's/smp$//g'`
 ( cat "`rpm -ql kernel-$KREL 2>/dev/null | grep /boot/config`"
   cat "`rpm -ql kernel-smp-$KREL 2>/dev/null | grep /boot/config`"
   cat "`dpkg -L linux-image-$KREL 2>/dev/null | grep /boot/config`"
   cat /boot/config-$KREL 2>/dev/null
 )

Works on most .rpm and .deb based distros. (If /proc/config.gz is 
present that could be added too.)

So if this was added as a 'make builtinconfig' kind of shortcut, 
with no extra steps needed (and if the script bailed out if it 
cannot find the currently booted .config) - that would be a rather 
useful (and easy) way to start kernel development on a new box.

Useful to newbies and oldbies alike IMHO.

	Ingo