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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 E0F21C433E0 for ; Wed, 8 Jul 2020 15:39:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B73122078D for ; Wed, 8 Jul 2020 15:39:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=telus.net header.i=@telus.net header.b="s5SXM0P+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730257AbgGHPjI (ORCPT ); Wed, 8 Jul 2020 11:39:08 -0400 Received: from cmta19.telus.net ([209.171.16.92]:50999 "EHLO cmta19.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729022AbgGHPjI (ORCPT ); Wed, 8 Jul 2020 11:39:08 -0400 Received: from dougxps ([173.180.45.4]) by cmsmtp with SMTP id tCA3jzWtbpULutCA4jlAgm; Wed, 08 Jul 2020 09:39:06 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=telus.net; s=neo; t=1594222746; bh=o5N79ZBHeiTcyL5ymZ08ngwvFVTh4xphD8Umxn4JnFU=; h=From:To:Cc:References:In-Reply-To:Subject:Date; b=s5SXM0P+vErz8gOrpU01BkGjcxTzi9PQDDoER2OXr0jOfsT4JtbMKiwvCGJQciqYN 6br6eGgCcHGf9R2euRI60arPXHWOhkGvHUQ3pJi7+AKBlkcwubRbFY/2JUkd/wY0i2 /FVIiQXgWHBiljc6R3cwP/PWe+gFjBo704J8O9/Es71D/NRMwts2tSfhd1YtjJQvg3 9sbTZOKELC4RbsGhaU/oUu7lbidP/oR2YUloo6qf0rDjO3Oz1Zq/jDBQBnz+BiToPH N7YWKjXJGId9ooQjnbLtnHXvL3+u8RZi+GFjFIltFcLSP2PCsgtSgGIV9byZYrkIl8 F71IbVBDU8g/A== X-Telus-Authed: none X-Authority-Analysis: v=2.3 cv=T9TysMCQ c=1 sm=1 tr=0 a=zJWegnE7BH9C0Gl4FFgQyA==:117 a=zJWegnE7BH9C0Gl4FFgQyA==:17 a=Pyq9K9CWowscuQLKlpiwfMBGOR0=:19 a=IkcTkHD0fZMA:10 a=XF7CgRh_bXJ1lIju71kA:9 a=peVjOHcpNOfjnLYI:21 a=NDR9TLrs6DQf6WNk:21 a=QEXdDO2ut3YA:10 From: "Doug Smythies" To: "'srinivas pandruvada'" Cc: "'Len Brown'" , "'Peter Zijlstra'" , "'Giovanni Gherdovich'" , "'Francisco Jerez'" , "'Linux PM'" , "'Rafael J. Wysocki'" References: <2931539.RsFqoHxarq@kreacher> <000001d6376a$03bbaae0$0b3300a0$@net> <000201d63776$2d56f330$8804d990$@net> <000b01d65535$d148b8c0$73da2a40$@net> In-Reply-To: Subject: RE: cpufreq: intel_pstate: HWP mode issue Date: Wed, 8 Jul 2020 08:39:02 -0700 Message-ID: <000c01d6553d$e9f59480$bde0bd80$@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: AdZVN7J7rlBfXP5BTdmqdsuXdUv+pAABOa2g X-CMAE-Envelope: MS4wfIqI8C2bvIokoCyiFxe+V/U2mF6NN0MxtdTYIAWJGkA7UdcpFBiQuIO0M1AMM1C77BfXj9UwYj7buu8ziRpXH7+/WiZuUtHSiOEtTh55WwRTWfLr2hPL 7mSDB17+ytG+D0h2PUbHfgQIU3PD1xFSYnpBfwmR/a/WYu0/OO3bGEAf05A8NLaAKm+y0G7qrq8Qn9fIgU9oWN2VUzr5fkAznmSNlDS2+kCarPVYFCGAC8dn LHK4JuZLbMIQOpB63JFoipR5i3eax5ITZDx8T6ddp1sCK2ZmRF0m2x034SK3SU0ZQ54pU/inT0LDdljFdEF9LTVZGdRCWz4VTNFqj/4qEaeEeXu1IpnkPF5F 9DLasq3dYujid5vBJNVvfiHFefhBJQ== Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 2020.07.08 07:54 srinivas pandruvada wrote: > On Wed, 2020-07-08 at 07:41 -0700, Doug Smythies wrote: > > On 2020.06.30 11:41 Doug Smythies wrote: ... > > > If the short sleep is somehow simultaneous with some sort of 5.0 > > > millisecond (200 Hertz) > > > periodic event (either in HWP itself, or via the driver, I am > > > unable to determine which, > > > but think it is inside the black box that is HWP), > > > > I have been attempting to characterise the "black box" that is HWP. > > In terms of system response verses EPP, I only observe the HWP loop > > time as the > > response variable. > > > > 0 <= EPP <= 1 : My test can not measure loop time. > > 2 <= EPP <= 39 : HWP servo loop time 2 milliseconds > > 40 <= EPP <= 55 : HWP servo loop time 3 milliseconds > > 56 <= EPP <= 79 : HWP servo loop time 4 milliseconds > > 80 <= EPP <= 133 : HWP servo loop time 5 milliseconds > > 134 <= EPP <= 143 : HWP servo loop time 6 milliseconds > > 144 <= EPP <= 154 : HWP servo loop time 7 milliseconds > > 155 <= EPP <= 175 : HWP servo loop time 8 milliseconds > > 176 <= EPP <= 255 : HWP servo loop time 9 milliseconds > > > > If there are other system response differences within > > those groups, I haven't been able to detect them, > > but would be grateful for any further insight. > > > > Otherwise, in future, I do not see a need to test anything > > other than 9 values of EPP, one from each group. > > > Thanks Doug, > I think they are enough. But there is no guarantee that every CPU model > will have same results as the power curve will be different. Yes, of course the response curve is different between CPU models. However, the basic loops times seem to be the same. Although I admit to having limited data from other CPU models. ... Doug