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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 E5367C43461 for ; Tue, 15 Sep 2020 17:59:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 853C621D43 for ; Tue, 15 Sep 2020 17:59:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="hEsZVQNw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727957AbgIOR6c (ORCPT ); Tue, 15 Sep 2020 13:58:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727758AbgIOR6O (ORCPT ); Tue, 15 Sep 2020 13:58:14 -0400 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FD82C061788 for ; Tue, 15 Sep 2020 10:58:10 -0700 (PDT) Received: by mail-pj1-x1031.google.com with SMTP id q4so180419pjh.5 for ; Tue, 15 Sep 2020 10:58:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=j+g2akO1lz2ozUn1CRIfY/0d2i70WKcJaWsW6RG6CLQ=; b=hEsZVQNwXVb5K4Iph8p76V23YfAj+k4SN8f0kxzSkN7p+uCYR8z/2IVqN8L06s78aF Sb7NcBWHJB36BAYQWVD5TRuWB52QF1dvWygLsshdIPk5pOmIlQEkuQXjV+clkEAeLJm0 o8/5GNFXs/MWQWMRSxjJXh2KYHFGnVWvi5xWk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=j+g2akO1lz2ozUn1CRIfY/0d2i70WKcJaWsW6RG6CLQ=; b=S5nwy12uUOchbwqUTiWMOlqZrhzZXE/3/N/fEcBsAFbmO3wL/pNPblq1yPjezcj5yC zC44Zt1O8SEksKZoj0aqUHuWBMncfsI5XvrGp9pcXcjqlSYzvs0PI1jm31hXpah3CqVI k0vRzD1d7h5VnL363I60y6U/XR4lhRHKY/+NAJ45ARgElbOSOyd1Q898vq2DBb3k0124 BtQATfFQ3H3riE8NngOF802KRuSpF9ZXOyMazqi7v7lCeBMBHVfR96SGsa+dAO3TZ19E Kt4pm0HpvSDvs9QEOzi48Yqxi8JlMXcDVs1/OmgZKX7gLWAulTnNjQgAVnzkYQmghvlQ CANw== X-Gm-Message-State: AOAM532tkCp2U24ITd8TnqulY+9bbzOTr1ax0DZ3WXPnHz2GTyxG4kk4 w+0IRXOni1hakrrwgK8VzD3cug== X-Google-Smtp-Source: ABdhPJzWSjusUL5iCMafqzidmc97rO1FaeMZvyldTmp4urHg5wJfBQZNJIuEoiZx9TlvbaxdNZZd1g== X-Received: by 2002:a17:902:b94b:b029:d1:e5f9:9f8 with SMTP id h11-20020a170902b94bb02900d1e5f909f8mr2678519pls.53.1600192689753; Tue, 15 Sep 2020 10:58:09 -0700 (PDT) Received: from localhost ([2620:15c:202:1:f693:9fff:fef4:e70a]) by smtp.gmail.com with ESMTPSA id k5sm14843618pfp.214.2020.09.15.10.58.09 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 15 Sep 2020 10:58:09 -0700 (PDT) Date: Tue, 15 Sep 2020 10:58:08 -0700 From: Matthias Kaehlcke To: Daniel Lezcano Cc: Rajendra Nayak , Lukasz Luba , Rob Herring , DTML , Doug Anderson , linux-pm@vger.kernel.org, Amit Daniel Kachhap , Viresh Kumar , Javi Merino Subject: Re: is 'dynamic-power-coefficient' expected to be based on 'real' power measurements? Message-ID: <20200915175808.GB2771744@google.com> References: <248bb01e-1746-c84c-78c4-3cf7d2541a70@codeaurora.org> <20200915172444.GA2771744@google.com> <406d5d4e-d7d7-8a37-5501-119b734facb3@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <406d5d4e-d7d7-8a37-5501-119b734facb3@linaro.org> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Tue, Sep 15, 2020 at 07:50:10PM +0200, Daniel Lezcano wrote: > On 15/09/2020 19:24, Matthias Kaehlcke wrote: > > +Thermal folks > > > > Hi Rajendra, > > > > On Tue, Sep 15, 2020 at 11:14:00AM +0530, Rajendra Nayak wrote: > >> Hi Rob, > >> > >> There has been some discussions on another thread [1] around the DPC (dynamic-power-coefficient) values > >> for CPU's being relative vs absolute (based on real power) and should they be used to derive 'real' power > >> at various OPPs in order to calculate things like 'sustainable-power' for thermal zones. > >> I believe relative values work perfectly fine for scheduling decisions, but with others using this for > >> calculating power values in mW, is there a need to document the property as something that *has* to be > >> based on real power measurements? > > > > Relative values may work for scheduling decisions, but not for thermal > > management with the power allocator, at least not when CPU cooling devices > > are combined with others that specify their power consumption in absolute > > values. Such a configuration should be supported IMO. > > The energy model is used in the cpufreq cooling device and if the > sustainable power is consistent with the relative values then there is > no reason it shouldn't work. Agreed on thermal zones that exclusively use CPUs as cooling devices, but what when you have mixed zones, with CPUs with their pseudo-unit and e.g. a GPU that specifies its power in mW?