From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2DB5C43381 for ; Sun, 17 Feb 2019 19:25:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8B77D218A1 for ; Sun, 17 Feb 2019 19:25:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=telus.net header.i=@telus.net header.b="DgELMZWE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726247AbfBQTZm (ORCPT ); Sun, 17 Feb 2019 14:25:42 -0500 Received: from cmta17.telus.net ([209.171.16.90]:51021 "EHLO cmta17.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725554AbfBQTZm (ORCPT ); Sun, 17 Feb 2019 14:25:42 -0500 Received: from dougxps ([173.180.45.4]) by cmsmtp with SMTP id vS4IgKUl8yWYLvS4KgMuTC; Sun, 17 Feb 2019 12:25:41 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=telus.net; s=neo; t=1550431541; bh=nhDHO7mckG1Jk3Ezhc0ys31dsSxz1g5J6L+kUHj/naY=; h=From:To:Cc:References:In-Reply-To:Subject:Date; b=DgELMZWEqQKsDxcO8Ask55QCyo25hgAv8YLhnF9HObuMOHlStIcjF6ZscK9Eqlfuv szseOfSokMlb++LFAcvDhjM3X0nL6B7f0oB0KUX2WrkG0Wv0NykK04Y3a0uSmRF1r+ Ya1YSbwFyKqsuN+eNhM9cYPrgl4XSjB1Hw26AEUBUh6AIqhvUx5kvdJasbk+HW1Tnl 6lInAkyiw/ZihveIITHd3S+gkwZ1JHhXQP5y3T3i+MRHE9cymPBMZC4axERnGC6s0q k3IwbkojndCqenki9HiRezcF81VdU8QVeI33axHBRt/Qo2UzsbsMH8LqZ6Bp5ZpXIy C9Z7l6keAK51w== X-Telus-Authed: none X-Authority-Analysis: v=2.3 cv=DalpVclW c=1 sm=1 tr=0 a=zJWegnE7BH9C0Gl4FFgQyA==:117 a=zJWegnE7BH9C0Gl4FFgQyA==:17 a=Pyq9K9CWowscuQLKlpiwfMBGOR0=:19 a=kj9zAlcOel0A:10 a=QyXUC8HyAAAA:8 a=Pq467yvRSnVCxoes1s0A:9 a=CjuIK1q_8ugA:10 From: "Doug Smythies" To: "'Rafael J. Wysocki'" , "'Linux PM'" Cc: "'Srinivas Pandruvada'" , "'LKML'" , "Doug Smythies" References: <2038590.kmssd2ZIyd@aspire.rjw.lan> <16144228.tcT5YVROcV@aspire.rjw.lan> In-Reply-To: <16144228.tcT5YVROcV@aspire.rjw.lan> Subject: RE: [PATCH v2] cpufreq: intel_pstate: Rework iowait boosting to be less aggressive Date: Sun, 17 Feb 2019 11:25:37 -0800 Message-ID: <000c01d4c6f6$914a7f20$b3df7d60$@net> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: AdS+25W+eJSwKn6ATzWfd7Ed+z8q9AGnaRjw Content-Language: en-ca X-CMAE-Envelope: MS4wfFMnuLyVu3WjYXJBZ6QfFQi4ICUhmPN7xSya1GxtiqEFR0m4Eo1UFrQSb8/6FKyX9Crrdl9lFjF2fGM5ZuANiEzb/535+yfNvbBjmirhm8ByuL6OLScf RpiD10qJ3Tmu++JQUg1cjEjm6toLZG+an7zSh1I9pH4XGAiXbMWifBZiDF/VZGmlatgekethBwnf7LYkVUw9D/CBYsh1ZYVgp9eTQZHL3BjSu5HnpDeSdS+4 8et9nUW40ccqyo/FJqT2ndD1o4Sr0DoEm3v1DtbpYEXEvrDp5LL7i5zkZcMNGLb7eauc+VKILGwKMaGpb+Ve2A== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019.02.07 03:51 Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > The current iowait boosting mechanism in intel_pstate_update_util() > is quite aggressive, as it goes to the maximum P-state right away, > and may cause excessive amounts of energy to be used, which is not > desirable and arguably isn't necessary too. > > Follow commit a5a0809bc58e ("cpufreq: schedutil: Make iowait boost > more energy efficient") that reworked the analogous iowait boost > mechanism in the schedutil governor and make the iowait boosting > in intel_pstate_update_util() work along the same lines. > > Signed-off-by: Rafael J. Wysocki > --- > > -> v2: > * Follow the Doug's suggestion and drop the immediate jump to > max P-state if boost is max. The code is simpler this way and > the perf impact should not be noticeable on average. Hi Rafael, Something has broken on my incoming e-mail sorting stuff, and I missed this one (and some others). This V2 is not actually what I was proposing. I was O.K. with the immediate jump, but I didn't want the set_pstate step by-passed if it was already at max because that would also by-pass the trace sample, if it was enabled. Anyway, this V2 seems O.K. to me. I tested it compared to V1 and, as you mentioned, wasn't able to detect any energy consumption or performance differences. ... Doug