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_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 81DE7C4CECE for ; Mon, 14 Oct 2019 14:33:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5894D21882 for ; Mon, 14 Oct 2019 14:33:31 +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="H2xn3tNq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732716AbfJNOda (ORCPT ); Mon, 14 Oct 2019 10:33:30 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:56848 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731121AbfJNOda (ORCPT ); Mon, 14 Oct 2019 10:33:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=oaPf6dnXppFrtIrvcvxSOzHPxnxg+Q1/gfUdnd2qqww=; b=H2xn3tNqupv4mtya7/ZVR254m sPEnCJnS3vkdQCoRyqO+jUcLVqIWn0yArybngv9Y/QprkEXIMMBTohbB/tX80eIhJ0mTAG+ldgtOE zXlQMqEFMaV+YT/MLRsA5k0Mv3229YPFlNOAsQiU7LGiqhxPsDQfp4WYM3rasClUBeLG8oOKZ3ejj XAkGg4jk7WvI58ZL6YeqQuTWV1quQM4vg0/88/i0Z0xlcqAaR2dg0DPLdeXsoVekNRqouuANEYa78 y9O6mvcqdoGQTFWXpN/Hp7MNEFmkHtZhc4mKCBBWVVAnguwRu0Wacw7KOehU1zDjWAyxvc3cet1JN +LaKorZrg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iK1PX-0001uU-97; Mon, 14 Oct 2019 14:33:23 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 2604C305E42; Mon, 14 Oct 2019 16:32:27 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 31E482026F768; Mon, 14 Oct 2019 16:33:21 +0200 (CEST) Date: Mon, 14 Oct 2019 16:33:21 +0200 From: Peter Zijlstra To: Douglas RAILLARD Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, mingo@redhat.com, rjw@rjwysocki.net, viresh.kumar@linaro.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, qperret@qperret.net, patrick.bellasi@matbug.net, dh.han@samsung.com Subject: Re: [RFC PATCH v3 4/6] sched/cpufreq: Introduce sugov_cpu_ramp_boost Message-ID: <20191014143321.GH2328@hirez.programming.kicks-ass.net> References: <20191011134500.235736-1-douglas.raillard@arm.com> <20191011134500.235736-5-douglas.raillard@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191011134500.235736-5-douglas.raillard@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Fri, Oct 11, 2019 at 02:44:58PM +0100, Douglas RAILLARD wrote: > Use the utilization signals dynamic to detect when the utilization of a > set of tasks starts increasing because of a change in tasks' behavior. > This allows detecting when spending extra power for faster frequency > ramp up response would be beneficial to the reactivity of the system. > > This ramp boost is computed as the difference > util_avg-util_est_enqueued. This number somehow represents a lower bound That reads funny, maybe 'as the difference between util_avg and util_est_enqueued' ? > of how much extra utilization this tasks is actually using, compared to > our best current stable knowledge of it (which is util_est_enqueued). > > When the set of runnable tasks changes, the boost is disabled as the > impact of blocked utilization on util_avg will make the delta with > util_est_enqueued not very informative. > @@ -561,6 +604,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) > } > } > > + > return get_next_freq(sg_policy, util, max); > } Surely we can do without this extra whitespace? :-)