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=-0.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID 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 0F798C43140 for ; Thu, 21 Jun 2018 18:57:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BEB0321A5C for ; Thu, 21 Jun 2018 18:57:21 +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="DCRxsVU9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BEB0321A5C 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 S933391AbeFUS5U (ORCPT ); Thu, 21 Jun 2018 14:57:20 -0400 Received: from merlin.infradead.org ([205.233.59.134]:60266 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933279AbeFUS5S (ORCPT ); Thu, 21 Jun 2018 14:57:18 -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=AnVC3KLNKApe38ml3rmsDOgF8AByKHygKBexbMQTpb0=; b=DCRxsVU9IuwwEwU2evAdiFeHR 5rmjW/vOBdBeMtuASK96mSO9U4ovra2B83oA+Pbcx3MyDNj5mdszp56aFVm0UPsTQLLHGWfI/lBot kXSnEaeKKFmCOAHBTKdgMvvM5e2Q2e/Yh7OsJ4+4qyOLayIvlUnlwakNrr4NUC/6Jkmv5DLP6cZJz epZxs9ZHLbatIeeO25ybXJi0hphIapvspQvZj/sNKyI5ACO6PWmMD6mrka4EXe32xZD24iHDOMM+D tfihs5oerFvLMfFrbCe3nMzZBUSaMUtemCXopWKwqp2UM2x/VPJGhx6w/XAM0pmukhYom197bREwR CzIK+SNgg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=worktop) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fW4lY-0000sj-9c; Thu, 21 Jun 2018 18:57:08 +0000 Received: by worktop (Postfix, from userid 1000) id DA0E26E093A; Thu, 21 Jun 2018 20:57:06 +0200 (CEST) Date: Thu, 21 Jun 2018 20:57:06 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, rjw@rjwysocki.net, juri.lelli@redhat.com, dietmar.eggemann@arm.com, Morten.Rasmussen@arm.com, viresh.kumar@linaro.org, valentin.schneider@arm.com, patrick.bellasi@arm.com, joel@joelfernandes.org, daniel.lezcano@linaro.org, quentin.perret@arm.com, Ingo Molnar Subject: Re: [PATCH v6 04/11] cpufreq/schedutil: use rt utilization tracking Message-ID: <20180621185706.GA4900@worktop.programming.kicks-ass.net> References: <1528459794-13066-1-git-send-email-vincent.guittot@linaro.org> <1528459794-13066-5-git-send-email-vincent.guittot@linaro.org> <20180621184524.GB27616@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180621184524.GB27616@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 21, 2018 at 08:45:24PM +0200, Peter Zijlstra wrote: > On Fri, Jun 08, 2018 at 02:09:47PM +0200, Vincent Guittot wrote: > > static unsigned long sugov_aggregate_util(struct sugov_cpu *sg_cpu) > > { > > struct rq *rq = cpu_rq(sg_cpu->cpu); > > + unsigned long util; > > > > if (rq->rt.rt_nr_running) > > return sg_cpu->max; > > > > + util = sg_cpu->util_dl; > > + util += sg_cpu->util_cfs; > > + util += sg_cpu->util_rt; > > + > > /* > > * Utilization required by DEADLINE must always be granted while, for > > * FAIR, we use blocked utilization of IDLE CPUs as a mechanism to > > @@ -197,7 +204,7 @@ static unsigned long sugov_aggregate_util(struct sugov_cpu *sg_cpu) > > * util_cfs + util_dl as requested freq. However, cpufreq is not yet > > * ready for such an interface. So, we only do the latter for now. > > */ > > - return min(sg_cpu->max, (sg_cpu->util_dl + sg_cpu->util_cfs)); > > + return min(sg_cpu->max, util); > > } > > So this (and the dl etc. equivalents) result in exactly the problems > complained about last time, no? > > What I proposed was something along the lines of: > > util = 1024 * sg_cpu->util_cfs; > util /= (1024 - (sg_cpu->util_rt + sg_cpu->util_dl + ...)); > > return min(sg_cpu->max, util + sg_cpu->bw_dl); > > Where we, instead of directly adding the various util signals. That looks unfinished; I think that wants to include: "we renormalize the CFS signal". > I now see an email from Quentin asking if these things are not in fact > the same, but no, they are not. The difference is that the above only > affects the CFS signal and will re-normalize the utilization of an > 'always' running task back to 1 by compensating for the stolen capacity. > > But it will not, like these here patches, affect the OPP selection of > other classes. If there is no CFS utilization (or very little), then the > renormalization will not matter, and the existing DL bandwidth > compuation will be unaffected. >