From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 0FB411A012C for ; Fri, 5 Sep 2014 17:39:47 +1000 (EST) Received: from e39.co.us.ibm.com (e39.co.us.ibm.com [32.97.110.160]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 36B5514009C for ; Fri, 5 Sep 2014 17:39:45 +1000 (EST) Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 5 Sep 2014 01:39:43 -0600 Received: from b01cxnp22033.gho.pok.ibm.com (b01cxnp22033.gho.pok.ibm.com [9.57.198.23]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 4571B6E8040 for ; Fri, 5 Sep 2014 03:39:28 -0400 (EDT) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id s857ddMJ7209306 for ; Fri, 5 Sep 2014 07:39:39 GMT Received: from d01av02.pok.ibm.com (localhost [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s857dceY023804 for ; Fri, 5 Sep 2014 03:39:39 -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 Date: Fri, 05 Sep 2014 13:09:32 +0530 Message-ID: <20140905073812.3629.29175.stgit@preeti.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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(-) --