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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, 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 434D4C6778C for ; Fri, 6 Jul 2018 15:50:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA2AF23F9C for ; Fri, 6 Jul 2018 15:50:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="hA78WjOB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA2AF23F9C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org 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 S933413AbeGFPu2 (ORCPT ); Fri, 6 Jul 2018 11:50:28 -0400 Received: from merlin.infradead.org ([205.233.59.134]:50052 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932849AbeGFPu1 (ORCPT ); Fri, 6 Jul 2018 11:50:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=dfY3oivKMcBdVLctdyJthSVHwUQTF8aaODT32hJl/R8=; b=hA78WjOBHttUg3gG923j7JG1f JJAjsOcl8oVeJPefSrLreT5ua8ZTnNjTQDae630m8K0gZGHM06qjQ9cUqr0dJ0hK9A8WawO4cG7OE NgUPQY+2Pc2325lgr1FJQjk2y7LCmKVSEpnZ6M5CdRoF02Jm9XUdXst4D1Rq+PcimarYkIjQhuVKs hMLk1+W34sifoNoUiG1wXfOTclkvaaJ07BtUeOgmmJXHFzFdKXg5PudGYsDw2IJZIUhaEgOT+n7VQ Ansic9InkLqGxNNsrPk4r3oTDJ5mA6Ww5u2u08ojWhzJt+fCOiQhFC2trcxSg4IWF1k4yUtpSgSg0 Nny7qHz9w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fbSzX-0002zW-Ll; Fri, 06 Jul 2018 15:49:51 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 4B7592028932D; Fri, 6 Jul 2018 17:49:49 +0200 (CEST) Date: Fri, 6 Jul 2018 17:49:49 +0200 From: Peter Zijlstra To: Quentin Perret Cc: rjw@rjwysocki.net, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, gregkh@linuxfoundation.org, mingo@redhat.com, dietmar.eggemann@arm.com, morten.rasmussen@arm.com, chris.redpath@arm.com, patrick.bellasi@arm.com, valentin.schneider@arm.com, vincent.guittot@linaro.org, thara.gopinath@linaro.org, viresh.kumar@linaro.org, tkjos@google.com, joel@joelfernandes.org, smuckle@google.com, adharmap@quicinc.com, skannan@quicinc.com, pkondeti@codeaurora.org, juri.lelli@redhat.com, edubezval@gmail.com, srinivas.pandruvada@linux.intel.com, currojerez@riseup.net, javi.merino@kernel.org Subject: Re: [RFC PATCH v4 09/12] sched/fair: Introduce an energy estimation helper function Message-ID: <20180706154949.GO2494@hirez.programming.kicks-ass.net> References: <20180628114043.24724-1-quentin.perret@arm.com> <20180628114043.24724-10-quentin.perret@arm.com> <20180706131243.GV2458@hirez.programming.kicks-ass.net> <20180706151212.GD17577@e108498-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180706151212.GD17577@e108498-lin.cambridge.arm.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 06, 2018 at 04:12:12PM +0100, Quentin Perret wrote: > On Friday 06 Jul 2018 at 15:12:43 (+0200), Peter Zijlstra wrote: > > Did you want to use sugov_get_util() here? There is no way we're going > > to duplicate all that. > > I need to look into how we can do that ... Sugov looks at the current > util landscape while EAS tries to predict the _future_ util landscape. > Merging the two means I need to add a task and a dst_cpu as parameters > of sugov_get_util() and call cpu_util_next() from there, which doesn't > feel so clean ... Just pass in the util_cfs as computed by cpu_util_next(), then schedutil will pass in cpu_util_cfs(), the rest is all the same I think. See below. > Also, if we merge sugov_get_util() and sugov_aggregate_util() with > Vincent's patch-set I'll need to make sure to return two values with > sugov_get_util(): 1) the sum of the util of all classes; and 2) the util > that will be used to request an OPP. 1) should be used in sum_util and > 2) could (but I don't think it's is a good idea) be used for max_util. I am confused, the max/sum thing is composed of the same values, just a different operator. Both take 'util': + util = schedutil_get_util(cpu, cpu_util_next(cpu, p, dst_cpu)) + max_util = max(util, max_util); + sum_util += util; unsigned long schedutil_get_util(int cpu, unsigned long util_cfs) { struct rq *rq = cpu_rq(cpu); unsigned long util, irq, max; max = arch_scale_cpu_capacity(NULL, cpu); if (rt_rq_is_runnable(&rq->rt)) return max; /* * Early check to see if IRQ/steal time saturates the CPU, can be * because of inaccuracies in how we track these -- see * update_irq_load_avg(). */ irq = cpu_util_irq(rq); if (unlikely(irq >= max)) return max; /* * Because the time spend on RT/DL tasks is visible as 'lost' time to * CFS tasks and we use the same metric to track the effective * utilization (PELT windows are synchronized) we can directly add them * to obtain the CPU's actual utilization. */ util = util_cfs; util += cpu_util_rt(rq); /* * We do not make cpu_util_dl() a permanent part of this sum because we * want to use cpu_bw_dl() later on, but we need to check if the * CFS+RT+DL sum is saturated (ie. no idle time) such that we select * f_max when there is no idle time. * * NOTE: numerical errors or stop class might cause us to not quite hit * saturation when we should -- something for later. */ if ((util + cpu_util_dl(rq)) >= max) return max; /* * There is still idle time; further improve the number by using the * irq metric. Because IRQ/steal time is hidden from the task clock we * need to scale the task numbers: * * 1 - irq * U' = irq + ------- * U * max */ util *= (max - irq); util /= max; util += irq; /* * Bandwidth required by DEADLINE must always be granted while, for * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism * to gracefully reduce the frequency when no tasks show up for longer * periods of time. * * Ideally we would like to set bw_dl as min/guaranteed freq and util + * bw_dl as requested freq. However, cpufreq is not yet ready for such * an interface. So, we only do the latter for now. */ return min(max, util + cpu_bw_dl(rq)); }