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 E5539C49EAB for ; Thu, 24 Jun 2021 20:44:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCC55613C2 for ; Thu, 24 Jun 2021 20:44:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232633AbhFXUrB (ORCPT ); Thu, 24 Jun 2021 16:47:01 -0400 Received: from alexa-out-sd-01.qualcomm.com ([199.106.114.38]:34438 "EHLO alexa-out-sd-01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230116AbhFXUrA (ORCPT ); Thu, 24 Jun 2021 16:47:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1624567480; x=1656103480; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=t61dWAbMMDRSTZHexoJmXU/Hc6CoxB6AF/BFYRLmSyg=; b=Bdqs5TgnQsKoKVZ3U230Ctws0YreyaoedmMKpiNGTpnfRm7ZWGzfxPxn ru9JJXdHT6vyzlHuxakk/D8DDMUqx/OYGL/h7AgT+7Luri3/7Y64sTFxF P/IgP+B9H5XZATaKER//htnZy1Nk6CIdgR8iLxa7Auqjl3PdnagBCwfai g=; Received: from unknown (HELO ironmsg05-sd.qualcomm.com) ([10.53.140.145]) by alexa-out-sd-01.qualcomm.com with ESMTP; 24 Jun 2021 13:44:40 -0700 X-QCInternal: smtphost Received: from nasanexm03e.na.qualcomm.com ([10.85.0.48]) by ironmsg05-sd.qualcomm.com with ESMTP/TLS/AES256-SHA; 24 Jun 2021 13:44:39 -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 13:44:37 -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: <81ea7ae0-54fd-85ba-b3de-a34520cb7f29@quicinc.com> Date: Thu, 24 Jun 2021 16:44:36 -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: nasanexm03d.na.qualcomm.com (10.85.0.91) To nasanexm03e.na.qualcomm.com (10.85.0.48) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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? FYI, the latest data point it that on the new kernel, the delivered performance does match the cpufreq_cur_freq. IOW, feedback_ctrs works fine. Also, "powersave" governor could bring down the scaling_cur_freq to scaling_min_freq. Right now, looks like the puzzles on this particular system as mentioned in the previous post are, 1) lowest_freq/lowest_perf != scaling_min_freq 2) CPPC + schedutil is not able to scale down CPUs.