kernel version

[jon]

On Sun, 2013-02-24 at 18:42 +0100, Marek Kubica wrote:
> On Sun, 24 Feb 2013 17:35:00 +0000
> jon <jon at jonshouse.co.uk> wrote:
> 
> > On Sun, 2013-02-24 at 18:06 +0100, Heinz-Jürgen Oertel wrote:
> > > Am Sonntag 24 Februar 2013, 15:36:15 schrieb jon:
> > > > I installed the latest version of raspian, got this kernel :
> > > > 
> > > > Linux raspberrypi 3.6.11+ #375 PREEMPT Tue Feb 12 01:41:07 GMT
> > > > 2013 armv6l GNU/Linux
> > > > 
> > > > Problem is I don't want PREEMPT as it unhelpful to my
> > > > application. 
> > > > 
> > > > A poke around with apt/synaptic does not show any other kernel
> > > > versions available.   How do I either change the kernel or
> > > > disable preemtion ?
> > > > 
> > > > Thanks,
> > > > Jon
> > > > 
> > > 
> > > Isn't as easy as editing .config 
> > > and saying
> > > CONFIG_PREEMPT_NONE=y
> > > # CONFIG_PREEMPT=y
> > > 
> > > or using menuconfig
> > > Processor type and features  ---> 
> > >    Preemption Model (Preemptible Kernel (Low-Latency Desktop))
> > > ---> Preemptible Kernel (Low-Latency Desktop) 
> > > 
> > > Regards
> > >     Heinz
> > 
> > Is this a "linux developer" easy - as in "need to install entire cross
> > compiler, and Pi specific patches, kernel sources, test build
> > environment etc" or normal human easy as in the Pi will build its own
> > kernel ?
> 
> No, you just boot it and compile the kernel on your device. That's what
> Linux users used to to a couple of years ago. I believe you can get the
> package sources via APT, then patch the config, build a .deb and
> install that to replace the kernel you don't like.
> 
> regards,
> Marek

Im dubious .....

Last time I checked the Broadcom specific nonsense was patched into the
kernel.  I cant find a raspian kernel sources package that corresponds
to the running kernel so i'm suspicious that it might not be as simple
as it should.  As is typical with linux its not documented and any docs
I find are out of date or don't correspond to the raspian specific
packages.  

Why the hell the preempt cant be toggled on/off from user space is a
mystery - its just a timer on an IRQ why cant I simply turn the timer
off. Maybe I can and its just not documented or I dont' know the cryptic
rune required to make it work :-( 

Ho hum ...

Thanks,
Jon