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 BCFBBC2D0F6 for ; Tue, 12 May 2020 15:49:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97AA4206DD for ; Tue, 12 May 2020 15:49:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kaDvjcGe" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730508AbgELPtq (ORCPT ); Tue, 12 May 2020 11:49:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726465AbgELPtq (ORCPT ); Tue, 12 May 2020 11:49:46 -0400 Received: from mail-qt1-x844.google.com (mail-qt1-x844.google.com [IPv6:2607:f8b0:4864:20::844]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C98D0C061A0C for ; Tue, 12 May 2020 08:49:44 -0700 (PDT) Received: by mail-qt1-x844.google.com with SMTP id i68so11451756qtb.5 for ; Tue, 12 May 2020 08:49:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=pK+4BJTjJjfcs5Luhl3I/0D6vtqlSzzqhFI0harskdY=; b=kaDvjcGevCgGbxVXAgEnCZsfj5UOf8oWOL7OfYa7+cQrQ4GBZFZNvB3N1g0jsvHHba AwbhmbLFaJS7OFfaqeo6muPspnUsP5MOLmVGvNIKhCLFncjkOMAxYAMtjK1w7ahqOIhC Z6c84ojmDWmqInRBsUrLZt9uHUXqvfhVWp5q9vkycCa3lMHutrDRyCuOzrqK3znuErx7 SQwGtis/NK+0HqKA/dX7YV08OctGVGL7jiFeTyYSOUMjGAlRUZC39Nkt/AXkigZ9PLLc G0ro4+ocK/NY1X3wb7x2W9HDVliltVgQjrzb7QC9brkA0jPE4qE1a3UH5S1UXx05KTUH M1Gw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=pK+4BJTjJjfcs5Luhl3I/0D6vtqlSzzqhFI0harskdY=; b=O5+sASc6zTo2IioqWZYxRZedx6uiBqnEbzs1ZbR2OoB7q0wlGF4jTNm9TWcG7wLEu7 aK7a84mNHDQviJdsThFMq3yUKKszl4SbdlSca2zAxOQXsBF2+JQ9r2GzdhjbSY0QXA58 +jz2jw0D/1nCzasfb7neSrE7ft7vSYxS/pKuPMr+DfXSB8mnb6FbBbMXhLz/8H8MdC0j 5OZ93CAcTEYweSDnekYRZ6vtI4Go3yWy67Sf+sbnHuB6XMDeleLmtLcEv9+aYjIlhjor BI+jXuUxIruid+XT6leF7aNrxFciDn9LZcyJ8f2e7OMabWGztA0sSmVnOUhFcIQ1Ti/A vUUQ== X-Gm-Message-State: AOAM530cQoT6IfmxtMq1vbP2WimHtZ+cXKqB6yyjE3+EniEMC6YAT/Ye OZIxi1gPswgUreZQJZmpoiU+BrBCvckpWl/LK+q28SrI X-Google-Smtp-Source: ABdhPJwIgpXmgCmWWESYLxeJ1HjN6UwWEz6IvBtfcgmPMm5bs3ZiBBqstYOlcwWmTphAhuGajF7bihfHxc98/8diw6w= X-Received: by 2002:aed:2967:: with SMTP id s94mr7784274qtd.278.1589298583628; Tue, 12 May 2020 08:49:43 -0700 (PDT) MIME-Version: 1.0 References: <20200508111612.GA252673@google.com> <20200508113141.GB5298@hirez.programming.kicks-ass.net> <20200508130507.GA10541@google.com> <20200511090049.GA229633@google.com> <20200512092102.GA16151@google.com> <20200512135813.GA101124@google.com> <20200512151120.GB101124@google.com> In-Reply-To: From: Joel Fernandes Date: Tue, 12 May 2020 11:49:32 -0400 Message-ID: Subject: Re: [PATCH 00/14] Modularize schedutil To: "Rafael J. Wysocki" Cc: Quentin Perret , Peter Zijlstra , Greg KH , Linux Kernel Mailing List , Linux PM , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "the arch/x86 maintainers" , "H. Peter Anvin" , Sudeep Holla , Viresh Kumar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Benjamin Segall , Mel Gorman , "Luis R. Rodriguez" , Kees Cook , Iurii Zaikin , Frederic Weisbecker , Todd Kjos , "Cc: Android Kernel" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 12, 2020 at 11:30 AM Rafael J. Wysocki wrote: [...] > > The end goal with GKI is the following: Google will release a single > > binary kernel image (signed, etc etc) that all devices using a given > > Android version will be required to use. That image is however going to > > be only for the core of the kernel (no drivers or anything of the sort). > > Vendors and OEMs, on their end, will be responsible to build and ship > > GKI-compatible modules for their respective devices. So, Android devices > > will eventually ship with a Google-issued GKI, plus a bunch of > > vendor-provided modules loaded during boot. > > If that is the case, then I absolutely think that schedutil should be > part of the GKI. > > Moreover, that would have been my opinion even if it had been modular > in the first place. > > > This is a significant shift from the current model where vendors > > completely own the kernel, and are largely free to use the kernel config > > they want. Today, those who don't use schedutil are free to turn the > > config off, for example. > > So why is this regarded as a good thing? > > > But GKI changes that. The 'core' GKI config is effectively imposed to > > the entire ecosystem. As of now, because it is 'bool' we have no choice > > but to compile schedutil in the core GKI as some (most) partners use it. > > But as you can imagine, that is not the preferred option of those who > > _don't_ use schedutil. > > OTOH, it may as well be an incentive for them to switch over and > report problems with it that they see. > > I absolutely would like to make schedutil the clearly preferred option > and IMO avoiding to use it, especially for non-technical reasons, > should be clearly less attractive. Also, does this series make it easier for vendors / oems / whoever to carry out-of-tree schedutil hacks saying that's "Ok" because that's not part of the core GKI? That would definitely be a bad thing to encourage as well. schedutil should pretty much be considered a part of the core GKI if the goal is to encourage everyone to move to it, IMO. - Joel