From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755933AbaIEHjp (ORCPT ); Fri, 5 Sep 2014 03:39:45 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:56722 "EHLO e8.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754415AbaIEHjo (ORCPT ); Fri, 5 Sep 2014 03:39:44 -0400 Subject: [PATCH V2 0/2] cpufreq/powernv: Set core pstate to a minimum just before hotplugging it out From: Preeti U Murthy To: viresh.kumar@linaro.org, rjw@rjwysocki.net Cc: linux-pm@vger.kernel.org, dirk.j.brandewie@intel.com, shreyas@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, patrick.marlier@gmail.com, linuxppc-dev@ozlabs.org, dirk.brandewie@gmail.com, svaidy@linux.vnet.ibm.com Date: Fri, 05 Sep 2014 13:09:32 +0530 Message-ID: <20140905073812.3629.29175.stgit@preeti.in.ibm.com> User-Agent: StGit/0.17-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14090507-0320-0000-0000-0000006741FB Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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] --- 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(-) --