Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932210AbcDAHUl (ORCPT ); Fri, 1 Apr 2016 03:20:41 -0400 Received: from cmta2.telus.net ([209.171.16.75]:53994 "EHLO cmta2.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757068AbcDAHUj convert rfc822-to-8bit (ORCPT ); Fri, 1 Apr 2016 03:20:39 -0400 X-Authority-Analysis: v=2.1 cv=GZDq5ljL c=1 sm=2 tr=0 a=zJWegnE7BH9C0Gl4FFgQyA==:117 a=zJWegnE7BH9C0Gl4FFgQyA==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=Pyq9K9CWowscuQLKlpiwfMBGOR0=:19 a=IkcTkHD0fZMA:10 a=fxJcL_dCAAAA:8 a=sXIeF0HFb3RiNN5mJfYA:9 a=QEXdDO2ut3YA:10 X-Telus-Outbound-IP: 173.180.45.4 From: "Doug Smythies" To: "=?UTF-8?Q?'J=C3=B6rg_Otte'?=" , "'Srinivas Pandruvada'" Cc: "'Rafael J. Wysocki'" , "'Linux Kernel Mailing List'" , , "'Rafael J. Wysocki'" References: <4187911.uaFVupaTVL@vostro.rjw.lan> <1459352017.13525.45.camel@intel.com> <002401d18ab5$0bf84a30$23e8de90$@net> <1459364336.13525.69.camel@linux.intel.com> <1459369587.13525.75.camel@linux.intel.com> In-Reply-To: Subject: RE: [intel-pstate driver regression] processor frequency very high even if in idle Date: Fri, 1 Apr 2016 00:20:32 -0700 Message-ID: <000d01d18be6$fae22a80$f0a67f80$@net> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: AdGLLv7MHgs7AILJQgirHrp+XHtjlAAo5YAg Content-Language: en-ca Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3777 Lines: 119 On 2016.03.31 02:24 Jörg Otte wrote: > 2016-03-30 22:26 GMT+02:00 Srinivas Pandruvada wrote: >> On Wed, 2016-03-30 at 22:12 +0200, Rafael J. Wysocki wrote: >>> On Wed, Mar 30, 2016 at 8:58 PM, Srinivas Pandruvada wrote: >>>> On Wed, 2016-03-30 at 11:50 -0700, Doug Smythies wrote: ... [cut]... >>>>>> Distro: Ubuntu 14.04.4 LTS >>>>>> Note that with Ubuntu 14.04, I had issues where my CPU >>>>>> would lock at pstate 24 (not always 24, but usually), >>>>>> regardless of load. >>>>>> However, it was always after an S3 suspend, occurred 100% >>>>>> of the time, and was independent of intel_pstate or >>>>>> acpi-cpufreq CPU frequency scaling drivers. >>>>>> >>>>>> Since changing my test server to Ubuntu server edition 16.04 >>>>>> (development version), I have not had those issues. While I have >>>>>> no proof, I have assumed the issue elimination was somehow >>>>>> related >>>>>> to the change to systemd. >>>>>> >>>>>> It might be worth observing both what the intel_pstate is asking >>>>>> for and what the processor is actually doing. >>>> If Jörg runs with >>>> >> turbostat -i 1 --msr=0x199 >> >> We can tell whether if we requested or the same problem you had. Yes, it proves that pstate was requested, but it does not disprove that the processor is in the locked up state. ...[cut]... > jojo@fichte:/sys/devices/system/cpu/cpufreq/policy0$ cat scaling_governor > powersave > turbostat -i 1 --msr=0x199 > CPUID(7): No-SGX > CPU Avg_MHz Busy% Bzy_MHz TSC_MHz MSR 0x199 > - 45 1.74 2590 2496 0x00000000 > 0 45 1.76 2565 2498 0x00000a00 > 1 72 2.84 2548 2496 0x00000800 > 2 30 1.11 2661 2496 0x00001a00 > 3 33 1.23 2661 2495 0x00001a00 > CPU Avg_MHz Busy% Bzy_MHz TSC_MHz MSR 0x199 > - 9 0.35 2525 2495 0x00000000 > 0 1 0.04 2735 2495 0x00000800 > 1 1 0.05 2501 2495 0x00000800 > 2 17 0.65 2540 2495 0x00001a00 > 3 16 0.64 2501 2495 0x00001a00 > CPU Avg_MHz Busy% Bzy_MHz TSC_MHz MSR 0x199 > - 11 0.43 2523 2495 0x00000000 > 0 3 0.11 2631 2495 0x00000c00 > 1 7 0.27 2524 2495 0x00000800 > 2 18 0.72 2527 2495 0x00001a00 > 3 15 0.61 2501 2495 0x00001a00 While there are other scenarios that would explain the data, it is consistent with the processor locked pstate scenario. The suggestion is to limit what the intel_pstate driver will ask for, and observe what is being given. Example (using my computer, which is working fine): 1.) What is the minimum? $ cat /sys/devices/system/cpu/intel_pstate/min_perf_pct 42 2.) Set the maximum the same as the minimum? $ sudo su root@s15:/home/doug/temp# root@s15:/home/doug/temp# echo "42" > /sys/devices/system/cpu/intel_pstate/max_perf_pct 3.) check it: root@s15:/home/doug/temp# cat /sys/devices/system/cpu/intel_pstate/max_perf_pct 42 3.) Observe what is being asked for and given: root@s15:/home/doug/temp# modprobe msr root@s15:/home/doug/temp# rdmsr --bitfield 15:8 -d -a 0x198 16 16 16 16 16 16 16 16 root@s15:/home/doug/temp# rdmsr --bitfield 15:8 -d -a 0x199 16 16 16 16 16 16 16 16 Jörg: As Srinivas mentioned, your kernel configuration is very odd. You mentioned you are using Ubuntu 14.04.4. Could you try the Ubuntu mainline kernel 4.6-rc1? You can get it here: http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.6-rc1-wily/ The reason I have been asking for trace data via a different method than Rafael and Srinivas, is because I use a set of post processing tools, originally created by the original intel_pstate driver maintainer. ... Doug