From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752297AbeCVGYw (ORCPT ); Thu, 22 Mar 2018 02:24:52 -0400 Received: from cmta17.telus.net ([209.171.16.90]:39079 "EHLO cmta17.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750886AbeCVGYu (ORCPT ); Thu, 22 Mar 2018 02:24:50 -0400 X-Authority-Analysis: v=2.2 cv=StJ/0LG0 c=1 sm=1 tr=0 a=zJWegnE7BH9C0Gl4FFgQyA==:117 a=zJWegnE7BH9C0Gl4FFgQyA==:17 a=Pyq9K9CWowscuQLKlpiwfMBGOR0=:19 a=IkcTkHD0fZMA:10 a=VwQbUJbxAAAA:8 a=HLEhOUT7AAAA:8 a=FGbulvE0AAAA:8 a=dk-T6pd_q-Q8p1Qg-z8A:9 a=QEXdDO2ut3YA:10 a=AjGcO6oz07-iQ99wixmX:22 a=73WewclNby-GrhdgABwy:22 a=svzTaB3SJmTkU8mK-ULk:22 From: "Doug Smythies" To: "'Rafael J. Wysocki'" , "'Thomas Ilsche'" Cc: "'Linux PM'" , "'Peter Zijlstra'" , "'Frederic Weisbecker'" , "'Thomas Gleixner'" , "'Paul McKenney'" , "'Rik van Riel'" , "'Aubrey Li'" , "'Mike Galbraith'" , "'LKML'" , "Doug Smythies" References: <2390019.oHdSGtR3EE@aspire.rjw.lan> <1635957.yuHkCe9oyz@aspire.rjw.lan> ym0ceyYVT1Konym0eegfln In-Reply-To: ym0ceyYVT1Konym0eegfln Subject: RE: [RFT][PATCH v7 5/8] cpuidle: Return nohz hint from cpuidle_select() Date: Wed, 21 Mar 2018 23:24:44 -0700 Message-ID: <002d01d3c1a6$7a06bc30$6e143490$@net> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Content-Language: en-ca Thread-Index: AdPBYg/Oh/zHpvmbQaGiHmKF6GMzzgAO92wg X-CMAE-Envelope: MS4wfNO/MuDUj+BV+Xbw+VZUPqn33hn06QC/+8VfvYricEhyTy2rCVDXilxSYVQwaflNQ+i+IthEoV0sj0leaRsQxX58XhXzb2OlkHhTqacpT8wdQ02ePGWF 8tiho3fnCZouBTrJAuuXtemAuf7IVrjl+xkjCzNO1pzz0jLJYuGK4MF3GXgta24/Ml56Uox74yN6LTCTsOjCo1VkFjxuepXj+j8zi2qqDjfS7F5jmChNMTR/ 7PCap3ZuNFttLKqZWWgDYN+eAyRfeoyQfYFe+7+rNNgiUWqj/31XJ2uwYoIgtTrDK5UGQwV+u7BqPk918XZZhhlI7lDgblaMx8GRtJNK28t3BWOnXWaAqPEa 4VCI2h0bFtqYb5HhSqeZUcSEQdoEb0nM5TxfeDDJDpQHll3mMwZRzM0FR7zeCpJup5Xxzr5XhP9FrrFsN+KXrjEvQ6Sb8AjmwWbrrIqx25obI9hp7CeYZDE6 U1B29YifCyHl1mbqwm87DkOtH5m87oE+j5ISnJOccrxBa3khyVZ8z2ZbOnU= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018.03.21 15:15 Rafael J. Wysocki wrote: > On Wed, Mar 21, 2018 at 6:59 PM, Thomas Ilsche wrote: >> On 2018-03-21 15:36, Rafael J. Wysocki wrote: >>> >>> >>> So please disregard this one entirely and take the v7.2 replacement >>> instead of it:https://patchwork.kernel.org/patch/10299429/ >>> >>> The current versions (including the above) is in the git branch at >>> >>> git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git \ >>> idle-loop-v7.2 >> >> With v7.2 (tested on SKL-SP from git) I see similar behavior in idle >> as with v5: several cores which just keep the sched tick enabled. >> Worse yet, some go only in C1 (not even C1E!?) despite sleeping the >> full sched tick. >> The resulting power consumption is ~105 W instead of ~ 70 W. >> >> https://wwwpub.zih.tu-dresden.de/~tilsche/powernightmares/v7_2_skl_sp_idle.png >> >> I have briefly ran v7 and I believe it was also affected. > > Then it looks like menu_select() stubbornly thinks that the idle > duration will be within the tick boundary on those cores. > > That may be because the bumping up of the correction factor in > menu_reflect() is too conservative or it may be necessary to do > something radical to measured_us in menu_update() in case of a tick > wakeup combined with a large next_timer_us value. > > For starters, please see if the attached patch (on top of the > idle-loop-v7.2 git branch) changes this behavior in any way. O.K. I am seeing some weirdness. On my system with both V7.2 and V7.2 plus this patch, I observe A spike in Idle State 1 residency every 34+ minutes. And slightly higher average idle power than before. (I might not have done V7 idle tests long enough). It can be seen in the frequency sweep I did earlier today, with V7.2: http://fast.smythies.com/rjw_freq_sweep_72_combined.png Despite the note on the graph that says it might be real, I don't think it is (I forgot to delete the note). With V7.2+ sometimes the event occurs at 17 minute intervals. Here is a idle graph (for reference: we have seen idle package power pretty steady at ~3.7 watts before). http://fast.smythies.com/rjw_v72p_idle.png ... Doug