From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755700AbdLVEqZ (ORCPT ); Thu, 21 Dec 2017 23:46:25 -0500 Received: from mail-pf0-f193.google.com ([209.85.192.193]:41701 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753926AbdLVEqV (ORCPT ); Thu, 21 Dec 2017 23:46:21 -0500 X-Google-Smtp-Source: ACJfBovNwi0DL/tsfOkWJWXaMbPibo9ZH8ZqpgG4Cyearf44WDYhb5ROqgvMvi5Li20SRsMeNweLNA== Date: Fri, 22 Dec 2017 10:16:16 +0530 From: Viresh Kumar To: Arnd Bergmann , rjw@rjwysocki.net Cc: Catalin Marinas , arm-soc , Will Deacon , Vincent Guittot , Linux Kernel Mailing List , Linux ARM Subject: Re: [PATCH] arm64: defconfig: Select schedutil as default cpufreq governor Message-ID: <20171222044616.GC8312@vireshk-i7> References: <20171215155040.mlvd56i2rfgd2e2t@armageddon.cambridge.arm.com> <20171218042917.GB19815@vireshk-i7> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21-12-17, 16:32, Arnd Bergmann wrote: > On Mon, Dec 18, 2017 at 5:29 AM, Viresh Kumar wrote: > > On 15-12-17, 15:50, Catalin Marinas wrote: > >> On Thu, Nov 16, 2017 at 11:51:36AM +0530, Viresh Kumar wrote: > >> > Currently performance governor is getting selected by default, which is > >> > surely not a very good choice as its pretty much power hungry. > >> > > >> > Select schedutil instead. > >> > >> And why do we care about this in defconfig? People deploying their own > >> kernels in mobile may opt for this config, others may prefer the default > >> governor. > >> > >> Also it seems it would be the only architecture make this governor the > >> default, so NAK. > > > > This is a bit dangerous configuration IMHO. > > > > Other architectures have some *real* governor selected by default, like Ondemand > > or Conservative. Running your CPUs at max (because of the default performance > > governor in arm64 config) may end up burning some SoCs accidentally just because > > their thermal stuff doesn't kick in to cool SoC down properly. > > > > So, we should have one of ondemand, conservative and schedutil selected by > > default for arm64 as well IMO and schedutil is the one which every one is > > falling back to now a days, even android. > > Maybe it's time to change the global 'default > CPU_FREQ_DEFAULT_GOV_PERFORMANCE' instead to avoid having to > do this for each architecture separately? > > I think the general idea of using schedutil or ondemand instead of performance > makes sense, but it doesn't feel right to have to do this for every > single defconfig > that doesn't select a default. +Rafael to see what his views are on this. -- viresh