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

From: Viresh Kumar
Date: Fri Sep 05 2014 - 03:41:27 EST


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>
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