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 04F7AC2D0FA for ; Wed, 13 May 2020 09:41:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3676206B8 for ; Wed, 13 May 2020 09:41:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="nbtBTs6X" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732480AbgEMJlZ (ORCPT ); Wed, 13 May 2020 05:41:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726645AbgEMJlY (ORCPT ); Wed, 13 May 2020 05:41:24 -0400 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 897ABC061A0E for ; Wed, 13 May 2020 02:41:23 -0700 (PDT) Received: by mail-wm1-x344.google.com with SMTP id n5so12806260wmd.0 for ; Wed, 13 May 2020 02:41:23 -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=NJBGaruknTCLtKKJk9/NPgVcIhnHRN5HOgLiTidMfps=; b=nbtBTs6Xx54r3xi5mFEcv4se2zQfkJy0cQh1tbJCIw8IoMzRCEr0oal1hCN8wgjJwG XJfDbD6yCAuuqlDeI7Ry1xErq+ap5T/xl3ude7Kf8KxrPAOkKt0I7tT+gue0xmLf03UW T7e5+LBwZVFtpdt1QkXQGwAyCQ8X7HkI6BligttJ82dncMKxLO6r9/fNTKcYJySDfwIR cRgHstp7X6H5NMznogdlwx1FUvoY9Ns4+KsmIXMTxizqrvkKIOMTkvUTVZDFaCJS2IkP yWiL85KWNcfvxM1s/c5bZSWwd3Y9ECI1Dc8APHKOiNg4ZliFiPwgPuftVHjIxUzlFmWi npSA== 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=NJBGaruknTCLtKKJk9/NPgVcIhnHRN5HOgLiTidMfps=; b=nNAYOHJjsuv/9tZMD2GPqnj47F3haauRN3dkHpJZmMMvLdDAK36sjPz/CCGhHXW3NH t95Q52lWXIxEnqped7OoUTygRR1qGP4UqM9QRwuWq4VYCpPWNZGGuWRWlPOdL8ivrvsl FQP1YneYqhXJVOvLQ4wS+x5lHQEc2CQikkFyh4BnZe3ChwAmg9xOoXVIQdN6g7DqOcM+ hua5rW+Ke5gIrvGd3MSBUZAxOay1atOUvR2R0ePMkJmLtCdsl69IP8QMx8NGR132hEXU JgFZfzFJen3HEA/uznu4FXiuWwhDdSj5NctU1znwpOqTy1/E52piPf4mYtsCJt/Ai1PC MfMQ== X-Gm-Message-State: AOAM530qQQEDWc2gy8xVedKvq+ykUI9YXhmkyaNVDPNJq1SS2Q/jwve/ 8zJiwFXxrsCvhUqV+VTKogCbhw== X-Google-Smtp-Source: ABdhPJxIzSvxktEk0dfkDZAgXrtWIO1vC88KrHWFh9dWQyFJ4zAsOGcxznMe+hx/MAUnWP+KEEw9nQ== X-Received: by 2002:a1c:6245:: with SMTP id w66mr7104946wmb.33.1589362881903; Wed, 13 May 2020 02:41:21 -0700 (PDT) Received: from google.com ([2a00:79e0:d:110:d6cc:2030:37c1:9964]) by smtp.gmail.com with ESMTPSA id x24sm28184249wrd.51.2020.05.13.02.41.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 May 2020 02:41:20 -0700 (PDT) Date: Wed, 13 May 2020 10:41:17 +0100 From: Quentin Perret To: "Rafael J. Wysocki" Cc: 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" Subject: Re: [PATCH 00/14] Modularize schedutil Message-ID: <20200513094117.GB225140@google.com> References: <20200511090049.GA229633@google.com> <20200512092102.GA16151@google.com> <20200512135813.GA101124@google.com> <20200512151120.GB101124@google.com> <20200512162630.GC101124@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rafael, On Tuesday 12 May 2020 at 19:30:52 (+0200), Rafael J. Wysocki wrote: > I don't see any technical reason for making schedutil modular in the > context of GKI other than to make the GKI image smaller, but I don't > expect that to be significant enough. The fact that we can make the image smaller, and we give vendors one less reason to not-want GKI _is_ desirable IMO. $ size vmlinux.* text data bss dec hex filename 19225963 9601976 491084 29319023 1bf5f6f vmlinux.after 19230599 9603236 491084 29324919 1bf7677 vmlinux.before ^ that's with the series applied. 'before' means sugov is =y, and 'after' is sugov =m. So modularizing saves just over 4K on text, and a bit of data too. Is it significant? Maybe not. But it's quite likely that those who don't use schedutil will find any unnecessary byte to be one too many. I just checked the size of modules in the default arm64 defconfig, and the median is ~4K of text. The average is a little bigger, but mostly because of a small number of really large modules (nouveau being the prime the example). So all in all, the sugov module is not particularly small by comparison with other things that have been modularized. A lot of small things can lead to significant savings at the end. Thanks, Quentin