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=-5.8 required=3.0 tests=BAYES_00,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 21C24C07E95 for ; Wed, 7 Jul 2021 10:32:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECA0861CCA for ; Wed, 7 Jul 2021 10:32:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231262AbhGGKfe (ORCPT ); Wed, 7 Jul 2021 06:35:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231276AbhGGKfd (ORCPT ); Wed, 7 Jul 2021 06:35:33 -0400 Received: from mail-lj1-x22c.google.com (mail-lj1-x22c.google.com [IPv6:2a00:1450:4864:20::22c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53471C061574 for ; Wed, 7 Jul 2021 03:32:53 -0700 (PDT) Received: by mail-lj1-x22c.google.com with SMTP id a6so2087204ljq.3 for ; Wed, 07 Jul 2021 03:32:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Wcak1Ofe83x621el2UdGBAdUl4Gwiq6BpwH465FUa/Q=; b=Y1qc5v5k67GQNdZB1sTiF7YHlYMBYpG/38vj5qm50DsU/b/FucLbo42Gv/QRHwGk4X 0931LHtXjhC95nZrs4IzuF3qbHRY9NYqfTd7aMMKUMU7vHyqhXTfFeMOMdDcGQVSyxO5 99J8eCiw5ZQ1/bx629RAszYcQ8iywZgns6J2Y7zn5Gh9q2HmdgNrUoPLaBp5ZQWxEEGs bDU2ffuWf3PxjZVEgwW10lxMMBChGTgSpnth64FwsLC2qclBwYbolQO98Omveqe7rOv4 CXo1FJWvkI0UuEIbbWLaxJ5ktB4MZcwQCvYC4Udq5Zuml5020M+f5kJyDX5mbwMrPbc8 jpTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Wcak1Ofe83x621el2UdGBAdUl4Gwiq6BpwH465FUa/Q=; b=Qpe0ziCnm9aVZU5xMdfMYaYWoyuj/xATKs1TeYHVRtcFhncifG9g0sjK8alNXqq5cW G496ZG634PEU1Vt/fSOfkFn+gKwTHWeZKal86DBNbX+w5SFGr27uCmNAJOmbccimWI91 4K3UFwdL1k2rxggbz8hucIaP3wFAo+sYiYpezI06aTUXU4IGX8Q2sSRMFHbKna2ZR3L6 xzhupGNM+h6QMqd1wf3gJz6fMMWn2f7LWIfo8FcAYL5HN0+xu51QXRWk0UtE6ufID9zB MXj3ZVJcby0ZvSjroQXqyExOKmwoXsvJvUCe5cuqIJlCqSqlOt3Sx69R3EhsOhIB6zC4 hlYQ== X-Gm-Message-State: AOAM533TI1ZvQtHCJUb227XSGhA6w5r+xEsUiiXAi6XGXuIcf+YfJLJK MJ1pboqJk7Y6c2481TO5pnZGWtwxzUAL/HEUwAHL0w== X-Google-Smtp-Source: ABdhPJyoGPaTT4NqVW7oko9qqSadcXDgrjhAb6CjaJY5L2LLlSJq4CCRMT8Am0i8tG6L0QTEE9k+/7shY9ecU/LKLW4= X-Received: by 2002:a2e:8941:: with SMTP id b1mr19154447ljk.284.1625653971625; Wed, 07 Jul 2021 03:32:51 -0700 (PDT) MIME-Version: 1.0 References: <20210625152603.25960-1-lukasz.luba@arm.com> <20210625152603.25960-2-lukasz.luba@arm.com> <2f43b211-da86-9d48-4e41-1c63359865bb@arm.com> <297df159-1681-f0a7-843d-f34d86e51d4c@arm.com> <27916860-33b1-f0a0-acff-4722a733c81b@arm.com> In-Reply-To: From: Vincent Guittot Date: Wed, 7 Jul 2021 12:32:40 +0200 Message-ID: Subject: Re: [PATCH 1/3] sched/fair: Prepare variables for increased precision of EAS estimated energy To: Lukasz Luba Cc: linux-kernel , Chris Redpath , Dietmar Eggemann , Morten Rasmussen , Quentin Perret , "open list:THERMAL" , Peter Zijlstra , "Rafael J. Wysocki" , Viresh Kumar , Ingo Molnar , Juri Lelli , Steven Rostedt , segall@google.com, Mel Gorman , Daniel Bristot de Oliveira , CCj.Yeh@mediatek.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Wed, 7 Jul 2021 at 12:29, Lukasz Luba wrote: > > > > On 7/7/21 11:11 AM, Vincent Guittot wrote: > > On Wed, 7 Jul 2021 at 12:06, Lukasz Luba wrote: > >> > > [snip] > > >> No. It's in 0.1uW scale, so 800Watts. Which is 16 CPUs * 64Watts > > > > Oh! you want 0.1uW precision .... This doesn't seem realistic at all. > > I'm not even sure that the power model can even reach an accuracy of > > 1mW > > > > True, the EM is registering platform with 1mW precision, but 1uW Do you mean 1uW or 0.1uW ? > precision makes more sense for internal EAS calculation. I don't > force platforms to report 1uW power, I just want to operate on > it internally. PowerCap and DTPM also operate internally on 1uW, > so it's not that unrealistic that some kernel components want > better resolution. > > But as Peter suggested, we might skip 32bit platforms for this issue. > I have to discussed this internally.