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=0.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,URIBL_DBL_ABUSE_MALW, 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 EF487C2D0DB for ; Mon, 27 Jan 2020 12:09:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD52B207FD for ; Mon, 27 Jan 2020 12:09:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730472AbgA0MJR (ORCPT ); Mon, 27 Jan 2020 07:09:17 -0500 Received: from foss.arm.com ([217.140.110.172]:43544 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729887AbgA0MJQ (ORCPT ); Mon, 27 Jan 2020 07:09:16 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EB16930E; Mon, 27 Jan 2020 04:09:15 -0800 (PST) Received: from [192.168.0.7] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 009303F52E; Mon, 27 Jan 2020 04:09:13 -0800 (PST) Subject: Re: [Patch v8 4/7] sched/fair: Enable periodic update of average thermal pressure To: Vincent Guittot Cc: Peter Zijlstra , Thara Gopinath , Ingo Molnar , Ionela Voinescu , Zhang Rui , Quentin Perret , Daniel Lezcano , viresh kumar , linux-kernel , Amit Kachhap , Javi Merino , Amit Kucheria References: <1579031859-18692-1-git-send-email-thara.gopinath@linaro.org> <1579031859-18692-5-git-send-email-thara.gopinath@linaro.org> <20200116151502.GQ2827@hirez.programming.kicks-ass.net> <20200117145544.GE14879@hirez.programming.kicks-ass.net> From: Dietmar Eggemann Message-ID: Date: Mon, 27 Jan 2020 13:09:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24/01/2020 16:45, Vincent Guittot wrote: > On Fri, 24 Jan 2020 at 16:37, Dietmar Eggemann wrote: >> >> On 17/01/2020 16:39, Vincent Guittot wrote: >>> On Fri, 17 Jan 2020 at 15:55, Peter Zijlstra wrote: >>>> >>>> On Fri, Jan 17, 2020 at 02:22:51PM +0100, Vincent Guittot wrote: >>>>> On Thu, 16 Jan 2020 at 16:15, Peter Zijlstra wrote: [...] >> The 'now' argument is one thing but why not: >> >> -int update_thermal_load_avg(u64 now, struct rq *rq, u64 capacity) >> +int update_thermal_load_avg(u64 now, struct rq *rq) >> { >> + u64 capacity = arch_cpu_thermal_pressure(cpu_of(rq)); >> + >> if (___update_load_sum(now, &rq->avg_thermal, >> >> This would make the call-sites __update_blocked_others() and >> task_tick(_fair)() cleaner. > > I prefer to keep the capacity as argument. This is more aligned with > others that provides the value of the signal to apply > >> >> I guess the argument is not to pollute pelt.c. But it already contains > > you've got it. I don't want to pollute the pelt.c file with things not > related to pelt but thermal as an example. > >> arch_scale_[freq|cpu]_capacity() for irq. But isn't arch_cpu_thermal_pressure() not exactly the same as arch_scale_cpu_capacity() and arch_scale_freq_capacity()? All of them are defined by default within the scheduler code [include/linux/sched/topology.h or kernel/sched/sched.h] and can be overwritten by arch code with a fast implementation (e.g. returning a per-cpu variable). So why is using arch_scale_freq_capacity() and arch_scale_cpu_capacity() in update_irq_load_avg [kernel/sched/pelt.c] and update_rq_clock_pelt() [kernel/sched/pelt.h] OK but arch_cpu_thermal_pressure() in update_thermal_load_avg() [kernel/sched/pelt.c] not? Shouldn't arch_cpu_thermal_pressure() not be called arch_scale_thermal_capacity() to highlight the fact that those three functions are doing the same thing, scaling capacity by something (cpu, frequency or thermal)?