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Subject: Re: [PATCH 2/4]: CPUIDLE: Introduce architecture independent
 cpuidle_pm_idle in drivers/cpuidle/cpuidle.c
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: arun@linux.vnet.ibm.com
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Date: Fri, 28 Aug 2009 08:40:11 +0200
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On Fri, 2009-08-28 at 10:19 +0530, Arun R Bharadwaj wrote:
> 
> 
> This only does the job of picking the right idle loop for current
> latency and power requirement. This is already done in ladder/menu
> governors under the routines menu_select()/ladder_select().
> I'm not sure whats the purpose of it here.

I can't seem to find ladder_select() but menu_select() doesn't manage
pm_idle and its not clear what it does manage.

> Here we are only concerned about the main idle loop, which is
> pm_idle/ppc_md.power_save. After setting the main idle loop to
> cpuidle_pm_idle, that would call cpuidle_idle_call() which would do
> the job of picking the right low level idle loop based on latency and
> other requirements.

It also gets pm_idle unexported and avoids anybody directly tinkering
with the function pointer, _that_ is the whole goal.

pm_idle is it exists today, and the whole cpuidle_{un,}install*() is
utter crap. It relies on unmanaged access to this function pointer.

/me stop looking at drivers/cpuidle/, convoluted mess that is, shame on
you for wanting to have anything to do with it.