From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1948667AbcBRX34 (ORCPT ); Thu, 18 Feb 2016 18:29:56 -0500 Received: from mga14.intel.com ([192.55.52.115]:20937 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1947103AbcBRX3x (ORCPT ); Thu, 18 Feb 2016 18:29:53 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,467,1449561600"; d="scan'208";a="749014846" From: "Pandruvada, Srinivas" To: "mgorman@techsingularity.net" , "rafael@kernel.org" CC: "matt@codeblueprint.co.uk" , "mingo@kernel.org" , "peterz@infradead.org" , "Brandewie, Dirk J" , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" , "rjw@rjwysocki.net" , "umgwanakikbuti@gmail.com" Subject: Re: [PATCH 1/1] intel_pstate: Increase hold-off time before busyness is scaled Thread-Topic: [PATCH 1/1] intel_pstate: Increase hold-off time before busyness is scaled Thread-Index: AQHRaqRDlXYOzVteNEi2oBXf7LQBkA== Date: Thu, 18 Feb 2016 23:29:51 +0000 Message-ID: <1455838105.7375.206.camel@intel.com> References: <1455793883-14214-1-git-send-email-mgorman@techsingularity.net> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.7.199.80] Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id u1INU0D6017937 On Thu, 2016-02-18 at 20:43 +0100, Rafael J. Wysocki wrote: > Hi Mel, > > On Thu, Feb 18, 2016 at 12:11 PM, Mel Gorman > wrote: > > [cut] > > > > > Signed-off-by: Mel Gorman > > --- > >  drivers/cpufreq/intel_pstate.c | 2 +- > >  1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > b/drivers/cpufreq/intel_pstate.c > > index cd83d477e32d..54250084174a 100644 > > --- a/drivers/cpufreq/intel_pstate.c > > +++ b/drivers/cpufreq/intel_pstate.c > > @@ -999,7 +999,7 @@ static inline int32_t > > get_target_pstate_use_performance(struct cpudata *cpu) > >         sample_time = pid_params.sample_rate_ms  * USEC_PER_MSEC; > >         duration_us = ktime_us_delta(cpu->sample.time, > >                                      cpu->last_sample_time); > > -       if (duration_us > sample_time * 3) { > > +       if (duration_us > sample_time * 12) { > >                 sample_ratio = div_fp(int_tofp(sample_time), > >                                       int_tofp(duration_us)); > >                 core_busy = mul_fp(core_busy, sample_ratio); > > -- > > I've been considering making a change like this, but I wasn't quite > sure how much greater the multiplier should be, so I've queued this > one up for 4.6. > We need to test power impact on different server workloads. So please hold on. We have server folks complaining that we already consume too much power. Thanks, Srinivas > That said please note that we're planning to make one significant > change to intel_pstate in the 4.6 cycle that's very likely to affect > your results. > > It is currently present in linux-next (commit 402c43ed2d74 "cpufreq: > intel_pstate: Replace timers with utilization update callbacks" in > the > linux-next branch of the linux-pm.git tree, that depends on commit > fe7034338ba0 "cpufreq: Add mechanism for registering utilization > update callbacks" in the same branch).  Also you can just pull from > the pm-cpufreq-test branch in linux-pm.git, but that contains much > more material. > > Thanks, > Rafael > -- > To unsubscribe from this list: send the line "unsubscribe linux-pm" > in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html