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

Arun R Bharadwaj arun at linux.vnet.ibm.com
Wed Oct 14 17:17:27 EST 2009

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

> Peter Zijlstra <a.p.zijlstra at 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.

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

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