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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 08336C433F4 for ; Mon, 24 Sep 2018 17:24:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C101320676 for ; Mon, 24 Sep 2018 17:23:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C101320676 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730243AbeIXX1I (ORCPT ); Mon, 24 Sep 2018 19:27:08 -0400 Received: from foss.arm.com ([217.140.101.70]:39278 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726133AbeIXX1H (ORCPT ); Mon, 24 Sep 2018 19:27:07 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A5FD380D; Mon, 24 Sep 2018 10:23:56 -0700 (PDT) Received: from e110439-lin (e110439-lin.Emea.Arm.com [10.4.12.126]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D75B73F5BD; Mon, 24 Sep 2018 10:23:53 -0700 (PDT) Date: Mon, 24 Sep 2018 18:23:51 +0100 From: Patrick Bellasi To: Peter Zijlstra Cc: Juri Lelli , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Ingo Molnar , Tejun Heo , "Rafael J . Wysocki" , Viresh Kumar , Vincent Guittot , Paul Turner , Quentin Perret , Dietmar Eggemann , Morten Rasmussen , Todd Kjos , Joel Fernandes , Steve Muckle , Suren Baghdasaryan Subject: Re: [PATCH v4 14/16] sched/core: uclamp: request CAP_SYS_ADMIN by default Message-ID: <20180924172351.GV1413@e110439-lin> References: <20180828135324.21976-15-patrick.bellasi@arm.com> <20180904134748.GA4974@localhost.localdomain> <20180906144053.GD25636@e110439-lin> <20180914111003.GC24082@hirez.programming.kicks-ass.net> <20180914140732.GR1413@e110439-lin> <20180914142813.GM24124@hirez.programming.kicks-ass.net> <20180917122723.GS1413@e110439-lin> <20180921091308.GD24082@hirez.programming.kicks-ass.net> <20180924151400.GT1413@e110439-lin> <20180924155616.GA7060@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180924155616.GA7060@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24-Sep 17:56, Peter Zijlstra wrote: > On Mon, Sep 24, 2018 at 04:14:00PM +0100, Patrick Bellasi wrote: > > On 21-Sep 11:13, Peter Zijlstra wrote: > > > Laptops with active cooling however... > > > > How do you see active cooling playing a role ? > > > > Are you thinking, for example, at reduced fan noise if we remain below > > a certain OPP ? > > > > Are you factoring fans power consumptions into the overall P consumption ? > > Nothing as fancy as that; I just figured that with a larger cooling > capacity, you can push chips higher onto that curve past the optimal > IPC/Watt point. Make it go fast etc.. That very concept of "optimal IPC/Watt" point is not something easy to define considering a monotonic function and without considering the specific optimization goals. It really sounds like saying that an LP problem has a unique solution independently from the optimization function. Do you think we should "mandate" an optimization function from kernel space? I'm not saying it does not make sense, but I find it at least a strong implementation enforcement. -- #include Patrick Bellasi