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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 21A9EC49EA7 for ; Thu, 24 Jun 2021 15:18:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 01114613DC for ; Thu, 24 Jun 2021 15:18:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231735AbhFXPUU (ORCPT ); Thu, 24 Jun 2021 11:20:20 -0400 Received: from alexa-out-sd-02.qualcomm.com ([199.106.114.39]:52566 "EHLO alexa-out-sd-02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231708AbhFXPUT (ORCPT ); Thu, 24 Jun 2021 11:20:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1624547880; x=1656083880; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=sAbysC06T03vfpgx6gVyg0DlqzJgM/bP3q40WfRjb4s=; b=uRFa1slBw5oyJZ49W/dnFjqTk57wdYLIVgShLt7zCLCZt3Rqz4WavV1c EVjURL1PBWnPtXwS7t+lghSSV4XHOfd29OUcryC1bdcXOK/5I6b7wSo9J SJtTcmBrDeQbOgQoTUg/cO8cxknYpYsRzFWwjJ54aBp/cszZnyJoq5TZ9 E=; Received: from unknown (HELO ironmsg-SD-alpha.qualcomm.com) ([10.53.140.30]) by alexa-out-sd-02.qualcomm.com with ESMTP; 24 Jun 2021 08:18:00 -0700 X-QCInternal: smtphost Received: from nasanexm03e.na.qualcomm.com ([10.85.0.48]) by ironmsg-SD-alpha.qualcomm.com with ESMTP/TLS/AES256-SHA; 24 Jun 2021 08:18:00 -0700 Received: from [10.111.163.161] (10.80.80.8) by nasanexm03e.na.qualcomm.com (10.85.0.48) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Thu, 24 Jun 2021 08:17:56 -0700 Subject: Re: [PATCH V3 0/4] cpufreq: cppc: Add support for frequency invariance To: Ionela Voinescu , Vincent Guittot CC: Viresh Kumar , Rafael Wysocki , Ben Segall , Daniel Bristot de Oliveira , Dietmar Eggemann , Greg Kroah-Hartman , Ingo Molnar , Juri Lelli , Mel Gorman , Peter Zijlstra , "Rafael J. Wysocki" , Steven Rostedt , Sudeep Holla , Will Deacon , "open list:THERMAL" , ACPI Devel Maling List , linux-kernel , "Paul E. McKenney" , "Rafael J. Wysocki" References: <09a39f5c-b47b-a931-bf23-dc43229fb2dd@quicinc.com> <20210623041613.v2lo3nidpgw37abl@vireshk-i7> <2c540a58-4fef-5a3d-85b4-8862721b6c4f@quicinc.com> <20210624025414.4iszkovggk6lg6hj@vireshk-i7> <20210624104734.GA11487@arm.com> From: Qian Cai Message-ID: Date: Thu, 24 Jun 2021 11:17:55 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210624104734.GA11487@arm.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nasanexm03e.na.qualcomm.com (10.85.0.48) Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On 6/24/2021 6:48 AM, Ionela Voinescu wrote: > Not if the counters are implemented properly. The kernel considers that > both reference and delivered performance counters should stop or reset > during idle. The kernel would not account for idle itself. > > If the reference performance counter does not stop during idle, while > the core performance counter (delivered) does stop, the behavior above > should be seen very often. > > Qian, do you see these small delivered performance values often or > seldom? Ionela, so I managed to upgrade the kernel on the system to today's linux-next which suppose to include this series. The delivered perf is now 280. However, scaling_min_freq (200 MHz) is not equal to lowest_perf (100). scaling_driver: acpi_cppc scaling_governor: schedutil Is that normal because lowest_nonlinear_perf is 200? Also, on this pretty idle system, 158 of 160 CPUs are always running in max freq (280 MHz). The other 2 are running in 243 and 213 MHz according to scaling_cur_freq. Apparently, "schedutil" does not work proper on this system. I am going to try other governors to narrow down the issue a bit. FYI, here is the acpi_cppc registers reading: /sys/devices/system/cpu/cpu0/acpi_cppc/feedback_ctrs ref:160705801 del:449594095 /sys/devices/system/cpu/cpu0/acpi_cppc/highest_perf 300 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_freq 1000 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_nonlinear_perf 200 /sys/devices/system/cpu/cpu0/acpi_cppc/lowest_perf 100 /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_freq 2800 /sys/devices/system/cpu/cpu0/acpi_cppc/nominal_perf 280 /sys/devices/system/cpu/cpu0/acpi_cppc/reference_perf 100 /sys/devices/system/cpu/cpu0/acpi_cppc/wraparound_time 18446744073709551615