From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srinivas Pandruvada Subject: Re: PROBLEM: Cpufreq constantly keeps frequency at maximum on 4.5-rc4 Date: Sun, 21 Feb 2016 12:02:28 -0800 Message-ID: <56CA17D4.8080802@linux.intel.com> References: <87egc7ahqn.fsf@iki.fi> <000401d16bfc$21338450$639a8cf0$@net> <87a8mv9ujm.fsf@iki.fi> <36DF59CE26D8EE47B0655C516E9CE640286C6253@shsmsx102.ccr.corp.intel.com> <87egc6zc2q.fsf@iki.fi> <36DF59CE26D8EE47B0655C516E9CE640286C6319@shsmsx102.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mga14.intel.com ([192.55.52.115]:9961 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750708AbcBUUCI (ORCPT ); Sun, 21 Feb 2016 15:02:08 -0500 In-Reply-To: <36DF59CE26D8EE47B0655C516E9CE640286C6319@shsmsx102.ccr.corp.intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Chen, Yu C" , Arto Jantunen Cc: Doug Smythies , "'Rafael J. Wysocki'" , 'Viresh Kumar' , "linux-pm@vger.kernel.org" On 02/21/2016 12:52 AM, Chen, Yu C wrote: >> -----Original Message----- >> From: Arto Jantunen [mailto:viiru@iki.fi] >> Sent: Sunday, February 21, 2016 4:45 PM >> To: Chen, Yu C >> Cc: Doug Smythies; 'Rafael J. Wysocki'; 'Viresh Kumar'; linux- >> pm@vger.kernel.org; 'Srinivas Pandruvada' >> Subject: Re: PROBLEM: Cpufreq constantly keeps frequency at maximum on >> 4.5-rc4 >> >> "Chen, Yu C" writes: >> >>>> -----Original Message----- >>>> From: linux-pm-owner@vger.kernel.org [mailto:linux-pm- >>>> owner@vger.kernel.org] On Behalf Of Arto Jantunen >>>> Sent: Sunday, February 21, 2016 1:11 AM >>>> To: Doug Smythies >>>> Cc: 'Rafael J. Wysocki'; 'Viresh Kumar'; linux-pm@vger.kernel.org; >>>> 'Srinivas Pandruvada' >>>> Subject: Re: PROBLEM: Cpufreq constantly keeps frequency at maximum >>>> on >>>> 4.5-rc4 >>>> >>>> "Doug Smythies" writes: >>>> >>>>> On 2106.02.20 00:50 Arto Jantunen wrote: >>>>>> I can force the frequency down manually with cpufreq-set, so the >>>>>> problem doesn't seem to be with the actual frequency changing. >>> cpufreq-set modifies the value of scaling_max_freq, it looks like >>> your system always demands for the max freq, can you provide: >>> grep . /sys/devices/system/cpu/intel_pstate/*perf_pct >>> under powersave and performance? >> Powersave: >> /sys/devices/system/cpu/intel_pstate/max_perf_pct:100 >> /sys/devices/system/cpu/intel_pstate/min_perf_pct:22 >> >> Performance: >> /sys/devices/system/cpu/intel_pstate/max_perf_pct:100 >> /sys/devices/system/cpu/intel_pstate/min_perf_pct:100 >> >> Also, adding intel_pstate=no_hwp to the command line does not change the >> result. Changing that to intel_pstate=disable does fix the problem, so the >> bug seems to be somewhere in intel_pstate instead of cpufreq core. You have Skylake, which is not compatible with legacy ACPI P states with _PSS tables, so not running without intel_pstate is not much use. It may be running at at low P-state by disabling. Is Debian use default mode as performance? I think Ubuntu uses performance mode as default. What is the output of cat cpu*/cpufreq/scaling_governor Thanks, Srinivas > 1.It would be nice if a git bisect is used to find the commit causing this problem. > > 2. > # cd /sys/kernel/debug/tracing/ > # echo 1 > events/power/pstate_sample/enable > # echo 1 > events/power/cpu_frequency/enable > # cat trace >