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 ACC2E1A012A for ; Tue, 9 Sep 2014 10:03:19 +1000 (EST) Received: from v094114.home.net.pl (v094114.home.net.pl [79.96.170.134]) by ozlabs.org (Postfix) with SMTP id C7D40140190 for ; Tue, 9 Sep 2014 10:03:16 +1000 (EST) From: "Rafael J. Wysocki" To: Viresh Kumar , Preeti U Murthy Subject: Re: [PATCH V2 0/2] cpufreq/powernv: Set core pstate to a minimum just before hotplugging it out Date: Tue, 09 Sep 2014 02:16:03 +0200 Message-ID: <7863288.1rO87QF8NW@vostro.rjw.lan> In-Reply-To: References: <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 Brandewie , Shreyas Prabhu , Linux Kernel Mailing List , Patrick Marlier , "linuxppc-dev@ozlabs.org" , Dirk Brandewie List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Friday, September 05, 2014 01:11:22 PM Viresh Kumar wrote: > On 5 September 2014 13:09, Preeti U Murthy 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 I've queued up the two patches for 3.18, thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.