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_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5A077C47254 for ; Fri, 8 May 2020 11:26:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37DBD208CA for ; Fri, 8 May 2020 11:26:31 +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="KLlSvJ6J" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727778AbgEHL0a (ORCPT ); Fri, 8 May 2020 07:26:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726618AbgEHL0a (ORCPT ); Fri, 8 May 2020 07:26:30 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B97AC05BD43; Fri, 8 May 2020 04:26:30 -0700 (PDT) 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; bh=i605eDMDNY8KyszY5v6QIxThK3xpDXQtG6gdo/y+ktg=; b=KLlSvJ6JY5ihQrVCCnT+wbVZgJ z3wpGMlGDZpsLvpDv7HIafxPs1yngTfy6fULgy9QRhhHGASaQ06FQm2v8cmhOBEmkoK4/J7vVN8tp aTZxlpudeb6U0tOfvdFCMTTE9KlxrTCbSnzfra1Mw059R2wKbxchrqwJkdQ7mtOG2M8prxNOqV8uJ nM2eLo5j/vASGAmjQtDWqNyWzZvhepI6Htw9ExmaxYnAl8wIeAen3lA4X9GR1/W+OiWUkYHjkO2PN Tp1j5aA81izfL94vE1bB4a6BMP6saHjBzm3isSsjsgyM/7dkfOKCas9GvS+LcA3VuauD1cpRS2xiB SJaonrUQ==; 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 1jX18t-0000MQ-Ly; Fri, 08 May 2020 11:26:11 +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 2D6B8301EFB; Fri, 8 May 2020 13:26:09 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1877B203ECDC2; Fri, 8 May 2020 13:26:09 +0200 (CEST) Date: Fri, 8 May 2020 13:26:09 +0200 From: Peter Zijlstra To: Greg KH Cc: Quentin Perret , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, sudeep.holla@arm.com, rafael@kernel.org, viresh.kumar@linaro.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, mcgrof@kernel.org, keescook@chromium.org, yzaikin@google.com, fweisbec@gmail.com, tkjos@google.com, kernel-team@android.com Subject: Re: [PATCH 00/14] Modularize schedutil Message-ID: <20200508112609.GA5298@hirez.programming.kicks-ass.net> References: <20200507181012.29791-1-qperret@google.com> <20200508081128.GM5298@hirez.programming.kicks-ass.net> <20200508103721.GA3860390@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200508103721.GA3860390@kroah.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 08, 2020 at 12:37:21PM +0200, Greg KH wrote: > On Fri, May 08, 2020 at 10:11:28AM +0200, Peter Zijlstra wrote: > > On Thu, May 07, 2020 at 07:09:58PM +0100, Quentin Perret wrote: > > > One challenge to implement GKI is to avoid bloating the kernel by > > > compiling too many things in, especially given that different devices > > > need different things. As such, anything that can be turned into a > > > module helps GKI, by offering an alternative to having that component > > > built-in. This is true for pretty much anything that can be made > > > modular, including drivers as well as other kernel components, such as > > > CPUFreq governors. > > > > The idea is to move to 1 governor, schedutil. Also, I abhor all the > > exports this thing does. Modules have no business touching most of that. > > > > Look at every EXPORT you do and wonder ask yourself how you can abuse > > it. Modules are not a good thing, they're horrible pieces of crap. > > Quentin, what is missing from schedutil that warrants the need for a > totally different governor? Is there specific problems with the > existing ones or is this just an instance of "we wrote our own a long > time ago and never pushed it upstream" from various SoC companies? At the very least there's that interactive governor that's really popular with Android. But IIRC there's a whole scala of home-brew governors and tweaks out there. And instead of enabling that crap, we should be discouraging it. Consolidate and kill the governor interface.