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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 C87B6C38A2A for ; Fri, 8 May 2020 13:10:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA479208CA for ; Fri, 8 May 2020 13:10:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="avte0Gre" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730205AbgEHNKL (ORCPT ); Fri, 8 May 2020 09:10:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1730448AbgEHNFN (ORCPT ); Fri, 8 May 2020 09:05:13 -0400 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3B32AC05BD43 for ; Fri, 8 May 2020 06:05:13 -0700 (PDT) Received: by mail-wr1-x443.google.com with SMTP id j5so1771125wrq.2 for ; Fri, 08 May 2020 06:05:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Mgb+elpG5rRocO3HltFPkQjaBpOGyLvzRk4WBy8PAxU=; b=avte0GreY98ChYX60EQHioHbWYFoHxkPBqNThycjj0bAXSB8OZZbe271eytzU9dx79 C8FaQBxFUZ3GDTVvIT89VXFjpubyrMz3G19/1aOKdIXTn4vnb1ZfFmqw5fFPbuWq5W+7 fcqkvekv1UgguYkRl/vJLoL7GHe8GeRdGahmEA1D5q7haPK3hPw/NTJTjop/8FgUb9Cu ZtUs2h0s5e6tX8bBwvwftZG29B6macEhAZBHu+SOo+SdXLM7r+Cf5OlIPqdOC42o/5EK r0nS1aOIpVSZdaGQKY9XMlRh19ORG1QdNiZPlngH8pXwdxZZtxNaGuyB1CbCDumVomaw UyTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Mgb+elpG5rRocO3HltFPkQjaBpOGyLvzRk4WBy8PAxU=; b=SjuJZiFkGBo5jI/K70QCVx5dn53cQkFBlS34Z+Pkr9UuZ5/76xbRCXPIpEl6bu2pYB LOhSkh+bYgC9iFt+nrgwmFXFVWIMKjLA288ozztc75zekuvD2FcHBkuoc8A0dLmUKHZL oWtfOl/SWQk7kQXIEcH4iQDOu2tZkNNQ4m/4uGLR2UzQeBdfq0FF5bSYQA5S7mH9nUZH nuQnUtborJ27HWPPeDK+OEoPQb5S5H4CqYU4Ow9qKGgm4YfgtCGKS+CXcbcAFDh4MCFc BcY+XP49uMRXjFHQuF8HS3q0I1eeKBaZ0p04bLTbaEG/7s8Emg67keHZeCEhRFJ49wDt v61g== X-Gm-Message-State: AGi0PuZixTUuEfeL1h1YGl4VswKOZB72yVGvLvWwY/q7IjD7b0rQvhsx FxDKsg1bG3H90so54PUQtelRSg== X-Google-Smtp-Source: APiQypLn2oiSKc2Okos29+vdEZOfH45zqdXlnILGJEI5IUubFXr251HgTQaCtZRYtPilMrWZhB6Vyw== X-Received: by 2002:adf:d841:: with SMTP id k1mr2812214wrl.129.1588943111589; Fri, 08 May 2020 06:05:11 -0700 (PDT) Received: from google.com ([2a00:79e0:d:110:d6cc:2030:37c1:9964]) by smtp.gmail.com with ESMTPSA id 5sm11892425wmg.34.2020.05.08.06.05.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 May 2020 06:05:10 -0700 (PDT) Date: Fri, 8 May 2020 14:05:07 +0100 From: Quentin Perret To: Peter Zijlstra Cc: Greg KH , 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: <20200508130507.GA10541@google.com> References: <20200507181012.29791-1-qperret@google.com> <20200508081128.GM5298@hirez.programming.kicks-ass.net> <20200508103721.GA3860390@kroah.com> <20200508111612.GA252673@google.com> <20200508113141.GB5298@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200508113141.GB5298@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday 08 May 2020 at 13:31:41 (+0200), Peter Zijlstra wrote: > On Fri, May 08, 2020 at 12:16:12PM +0100, Quentin Perret wrote: > > However, the point I tried to make here is orthogonal to that. As of > > today using another governor than schedutil is fully supported upstream, > > and in fact it isn't even enabled by default for most archs. If vendors > > feel like using something else makes their product better, then I don't > > see why I need to argue with them about that. And frankly I don't see > > that support being removed from upstream any time soon. > > Right, it'll take a while to get there. But that doesn't mean we > shouldn't encourage schedutil usage wherever and whenever possible. That > includes not making it easier to not use it. > > In that respect making it modular goes against our ultimate goal (world > domination, ). Right, I definitely understand the sentiment. OTOH, things like that give vendors weapons against GKI ('you-force-us-to-build-in-things-we-dont't-want' etc etc). That _is_ true to some extent, but it's important we make sure to keep this to an absolute minimum, otherwise GKI just won't happen (and I really think that'd be a shame, GKI _is_ a good thing for upstream). And sure, schedutil isn't that big, and we can make an exception. But I'm sure you know what happens when you starting making exceptions ;) So, all in all, I don't think the series actively makes schedutil worse by adding out-of-line calls in the hot path or anything like that, and having it as a module helps with GKI which I'm arguing is a good thing in the grand scheme of things. That of course is only true if we can agree on a reasonable set of exported symbols, so I'll give others some time to complain and see if I can post a v2 addressing these issues! Cheers, Quentin