Re: [PATCH V2 0/2] cpufreq/powernv: Set core pstate to a minimum just before hotplugging it out

From: Rafael J. Wysocki
Date: Mon Sep 08 2014 - 19:56:41 EST


On Friday, September 05, 2014 01:11:22 PM Viresh Kumar wrote:
> On 5 September 2014 13:09, Preeti U Murthy <preeti@xxxxxxxxxxxxxxxxxx> wrote:
> > Today cpus go to winkle when they are offlined. Since it is the deepest
> > idle state that we have, it is expected to save good amount of power as compared
> > to online state, where cores can enter nap/fastsleep only which are
> > shallower idle states.
> > However we observed no powersavings with winkle as compared to nap/fastsleep
> > and traced the problem to the pstate of the core being kept at a high even
> > when the core is offline. This can keep the socket pstate high, thus burning
> > power unnecessarily. This patchset fixes this issue.
> >
> > Changes in V2: Changed smp_call_function_any() to smp_call_function_single() in Patch[2/2]
>
> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

I've queued up the two patches for 3.18, thanks!

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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