Re: [v8 PATCH 2/8]: cpuidle: implement a list based approach to register a set of idle routines.

Arun R Bharadwaj
2009-10-14T06:17:27Z

* Andi Kleen <andi@firstfloor.org> [2009-10-12 20:00:05]:

> Peter Zijlstra <a.p.zijlstra@chello.nl> writes:
> >
> > So does it make sense to have a set of sets?
> >
> > Why not integrate them all into one set to be ruled by this governor
> > thing?
>
> cpuidle is currently optional, that is why the two level hierarchy
> is there so that you can still have simple idle selection without it.
>
> % size drivers/cpuidle/*.o
> text data bss dec hex filename
> 5514 1416 44 6974 1b3e drivers/cpuidle/built-in.o
>
> Adding it unconditionally would add ~7k to everyone who wants idle functions.
>
> I think making it unconditional would require putting it on a serious
> diet first.
>

Hi Andi,

Yes, this is a valid point.

How about something like this..
If the arch does not enable CONFIG_CPU_IDLE, the cpuidle_idle_call
which is called from cpu_idle() should call default_idle without
involving the registering cpuidle steps. This should prevent bloating
up of the kernel for archs which dont want to use cpuidle.

--arun
> -Andi
> --
> ak@linux.intel.com -- Speaking for myself only.