From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751953AbeCWDTe (ORCPT ); Thu, 22 Mar 2018 23:19:34 -0400 Received: from cmta19.telus.net ([209.171.16.92]:53547 "EHLO cmta19.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751861AbeCWDTc (ORCPT ); Thu, 22 Mar 2018 23:19:32 -0400 X-Authority-Analysis: v=2.2 cv=TI+qcxta c=1 sm=1 tr=0 a=zJWegnE7BH9C0Gl4FFgQyA==:117 a=zJWegnE7BH9C0Gl4FFgQyA==:17 a=Pyq9K9CWowscuQLKlpiwfMBGOR0=:19 a=IkcTkHD0fZMA:10 a=iQQjKHJntgW4jRJZ_nkA:9 a=QEXdDO2ut3YA:10 From: "Doug Smythies" To: "'Rik van Riel'" , "'Rafael J. Wysocki'" Cc: "'Linux PM'" , "'Frederic Weisbecker'" , "'Thomas Gleixner'" , "'Paul McKenney'" , "'Thomas Ilsche'" , "'Aubrey Li'" , "'Mike Galbraith'" , "'LKML'" , "'Peter Zijlstra'" , "Doug Smythies" References: <4137867.C4jYrWdt8n@aspire.rjw.lan> <20180314120450.GT4043@hirez.programming.kicks-ass.net> z38ge3YFh1Konz38iel45g z5HFe4V4W1Konz5chemDYc In-Reply-To: z5HFe4V4W1Konz5chemDYc Subject: RE: [PATCH v2] cpuidle: poll_state: Add time limit to poll_idle() Date: Thu, 22 Mar 2018 20:19:24 -0700 Message-ID: <004c01d3c255$c1f146a0$45d3d3e0$@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: AdPB+2Knq1MUfUhjTr6ehdQ6RKf0qwAFSacQABDbwHA= X-CMAE-Envelope: MS4wfDJzHJyax60fwZKoDIqT/r49hCoqOgxAY7DEEWozSSdfEM7Ss/HsuEChEumhXPOuZzt1HSnyoADU+DxO9TnZN0YkSX01cmu2SXc1n/eu7P26/Q0nUudS oBM2fVRlAqAyUdpTBz0uSO57uEP5xKbM4kWMhcA9d5sct1n1NP7c/5S1giFmqYcfSiAT/FwPWSOqJ1xjpvjS+Seok+zVzy8DJ+SATvbOsHNuzTi/CTdJfgBR +5nE7+SgXRD4DzShMYheixHPIQW1DjmooJjF06MdhyBFCiFr1l66Sfy/GE8MAmxRa5umtcKlNU3m/z1LKOVGULW8niuGvbCFNXgiFsUX6HDcKudQzolkWgJV aa73yFKaILQ/1egCxAlol+OjdX2ecobCULaP+PxrEdwHhvUETJVXS2zjxEzCh3opp7NzoJvF9qNkAy+YJDgdRRimISDXAj6wN9mBQqxIXlxEbiU3OuDEvhej K24AoGzbZ4gwkWCrwx4+UrYkn5G6G65FUSXM4LaLKkXABgOd/kX4qbLXYlU= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018.03.22 12:12 Doug Smythies wrote: >On 2018.03.22 09:32 Rik van Riel wrote: >> On Wed, 2018-03-14 at 13:04 +0100, Peter Zijlstra wrote: >> >>> On x86 we don't have to use that time_check_counter thing, >>> sched_clock() >>> is really cheap, not sure if it makes sense on other platforms. >> >> Are you sure? I saw a 5-10% increase in CPU use, >> for a constant query rate to a memcache style >> workload, with v3 of this patch. > > I would very much like to be able to repeat your test results. > However, I am not sure what you mean by "memcache style workload". > Is there a test you can point me to? Say a Phoronix type test, for example. > > All of my tests with the V3 of this patch have been fine. What is the difference between sched_clock() talked about herein, and local_clock() used in the patch? I'm not sure how good it is but I made a test. I didn't believe the results, so I did it 3 times. V7.3 is as from the git branch. V7.3p is plus the patch adding the counter loop to poll_state.c The test is a tight loop (about 19600 loops per second) running on all 8 CPUs. I can not seem to get my system to use Idle State 0, so I disabled Idle States 1 and 2 to force use of Idle State 0. V7.3 uses a processor package power of 62.5 Watts V7.3p uses a processor package power of 53.4 Watts, or 14.6% less power. The loop times do not change. The Idle state 0 residency per unit time does not change. ... Doug