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 D28D2C2B9F4 for ; Sat, 26 Jun 2021 02:29:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4C3161926 for ; Sat, 26 Jun 2021 02:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229999AbhFZCb4 (ORCPT ); Fri, 25 Jun 2021 22:31:56 -0400 Received: from alexa-out-sd-02.qualcomm.com ([199.106.114.39]:2457 "EHLO alexa-out-sd-02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229782AbhFZCby (ORCPT ); Fri, 25 Jun 2021 22:31:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1624674573; x=1656210573; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=OzVDDKY5xaLH3FGbd2mDr5h3AyjjviKx2toZSojncrg=; b=irO7A5ACWUHR/cSxmXi6bWGOeyX8ob/elhPHO+TG6D3Ne4B5nD6RFI1c 3g1RoJeEDyOZ+ezCQEL0JMRmu4dnVgN/fu8UIERvFoB06lKFAlWkZkvz1 xm8eEpJmW99nQ3ew4gkY1lOo6Tx3SMlz3YuRPMd3xhnryJEdrnn5FMLP6 0=; Received: from unknown (HELO ironmsg04-sd.qualcomm.com) ([10.53.140.144]) by alexa-out-sd-02.qualcomm.com with ESMTP; 25 Jun 2021 19:29:30 -0700 X-QCInternal: smtphost Received: from nasanexm03e.na.qualcomm.com ([10.85.0.48]) by ironmsg04-sd.qualcomm.com with ESMTP/TLS/AES256-SHA; 25 Jun 2021 19:29:30 -0700 Received: from [10.111.161.13] (10.80.80.8) by nasanexm03e.na.qualcomm.com (10.85.0.48) with Microsoft SMTP Server (TLS) id 15.0.1497.18; Fri, 25 Jun 2021 19:29:27 -0700 Subject: Re: [PATCH V3 0/4] cpufreq: cppc: Add support for frequency invariance To: Ionela Voinescu CC: Vincent Guittot , 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> <20210625102113.GB15540@arm.com> <1f83d787-a796-0db3-3c2f-1ca616eb1979@quicinc.com> <20210625143713.GA7092@arm.com> From: Qian Cai Message-ID: <888b0178-00cc-ffa4-48a2-8563cef557a4@quicinc.com> Date: Fri, 25 Jun 2021 22:29:26 -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: <20210625143713.GA7092@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: nasanexm03h.na.qualcomm.com (10.85.0.50) To nasanexm03e.na.qualcomm.com (10.85.0.48) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/25/2021 10:37 AM, Ionela Voinescu wrote: > Quick questions for you: > > 1. When you say you tried a 5.4 kernel, did you try it with these > patches backported? They also have some dependencies with the recent > changes in the arch topology driver and cpufreq so they would not be > straight forward to backport. > > If the 5.4 kernel you tried did not have these patches, it might be best > to try next/master that has these patches, but with > CONFIG_ACPI_CPPC_CPUFREQ_FIE=n, just to eliminate the possibility that > an incorrect frequency scale factor here would affect utilization that > would then affect the schedutil frequency selection. I would not expect > this behavior even if the scale factor was wrong, but it would be good > to rule out. > > 2. Is your platform booting with all CPUs? Are any hotplug operations > done in your scenario? Ionela, I found that set ACPI_PROCESSOR=y instead of ACPI_PROCESSOR=m will fix the previous mentioned issues here (any explanations of that?) even though the scaling down is not perfect. Now, we have the following on this idle system: # cat /sys/devices/system/cpu/*/cpufreq/cpuinfo_cur_freq | sort | uniq -c 79 1000000 1 1160000 73 1400000 1 2000000 4 2010000 1 2800000 1 860000 Even if I rerun a few times, there could still have a few CPUs running lower than lowest_perf (1GHz). Also, even though I set all CPUs to use "userspace" governor and set freq to the lowest. A few CPUs keep changing at will. # cat /sys/devices/system/cpu/*/cpufreq/cpuinfo_cur_freq | sort | uniq -c 156 1000000 3 2000000 1 760000