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=-2.2 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, 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 20DA3C65BAE for ; Thu, 13 Dec 2018 14:04:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D2DF320849 for ; Thu, 13 Dec 2018 14:04:30 +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="vxPjTDxs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D2DF320849 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 S1728645AbeLMOEa (ORCPT ); Thu, 13 Dec 2018 09:04:30 -0500 Received: from merlin.infradead.org ([205.233.59.134]:48610 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728020AbeLMOE3 (ORCPT ); Thu, 13 Dec 2018 09:04:29 -0500 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=1xIDpfvBryUFGZJwqlARgvbYfUBrfWMTyTLvLb+WPhs=; b=vxPjTDxshp1GGRkYs+jP7nbkH Sx406rOu9WbWowjjcqZRs71kcLVu5Q53U86WkA7HXM4RrucomX5PJO/i5SB0+IwRU0PITugdrm4n6 9AMnqJiOvos4gH0bDDLqlk6kO9VLChZQ5Y+siqry+EO7+B96O2UtE8vPXRJVZNiQJsndvBbiPC1eC P45LKWEnMLOsmCMxV6wtpO69FRjPkkQ5qsOVBgQOPOQlcH0anUFwV/CzNRzRSUO818aXOSiC17b26 GJxt02rBKVZPLsdkdfgG/vEmDW1644NW+JNnVBjdutttoYICpffH45W4JQ0leMBTGGfy9fJ8s/sNK tZxe7je4w==; 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 1gXRaq-0004YE-ET; Thu, 13 Dec 2018 14:04:00 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 014EF207264E1; Thu, 13 Dec 2018 15:03:58 +0100 (CET) Date: Thu, 13 Dec 2018 15:03:58 +0100 From: Peter Zijlstra To: Quentin Perret Cc: Ingo Molnar , 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@codeaurora.org, skannan@codeaurora.org, pkondeti@codeaurora.org, juri.lelli@redhat.com, edubezval@gmail.com, srinivas.pandruvada@linux.intel.com, currojerez@riseup.net, javi.merino@kernel.org Subject: Re: [PATCH v10 10/15] sched: Introduce a sysctl for Energy Aware Scheduling Message-ID: <20181213140358.GJ5289@hirez.programming.kicks-ass.net> References: <20181203095628.11858-1-quentin.perret@arm.com> <20181203095628.11858-11-quentin.perret@arm.com> <20181211141509.GA32005@gmail.com> <20181211144901.hio4b6aw3esw3cgw@queper01-lin> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181211144901.hio4b6aw3esw3cgw@queper01-lin> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 11, 2018 at 02:49:01PM +0000, Quentin Perret wrote: > Hi Ingo, > > On Tuesday 11 Dec 2018 at 15:15:09 (+0100), Ingo Molnar wrote: > > > > * Quentin Perret wrote: > > > > > In its current state, Energy Aware Scheduling (EAS) starts automatically > > > on asymmetric platforms having an Energy Model (EM). However, there are > > > users who want to have an EM (for thermal management for example), but > > > don't want EAS with it. > > > > Well, then introduce a new Kconfig variant for EAS, if it's super > > important to allow this to be disabled. > > > > Why do we want to disable it - is it not reliable in some circumstances? > > There are people out there using big.little systems who do not care > about energy. Not very many of them, that is true, but they exist. And > those people can be interested in having an Energy Model for > IPA/thermal but also want to spread tasks to minimize latency for > example. So those guys will appreciate a knob, I think. Otherwise EAS > gets enabled/disabled only by side effects (by enabling/disabling > schedutil for example). Right, also we have a sysctl for numa-balancing, I figured having one for eas would not be weird.