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.
---
Preeti U Murthy (2):
cpufreq: Allow stop CPU callback to be used by all cpufreq drivers
powernv/cpufreq: Set the pstate of the last hotplugged out cpu in
policy->cpus to minimum
drivers/cpufreq/cpufreq.c | 2 +-
drivers/cpufreq/powernv-cpufreq.c | 9 +++++++++
2 files changed, 10 insertions(+), 1 deletion(-)
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