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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6930ECAAD3 for ; Fri, 9 Sep 2022 06:22:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 230928D0005; Fri, 9 Sep 2022 02:22:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1DF778D0002; Fri, 9 Sep 2022 02:22:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0A8268D0005; Fri, 9 Sep 2022 02:22:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id F02788D0002 for ; Fri, 9 Sep 2022 02:22:45 -0400 (EDT) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id C286B14069F for ; Fri, 9 Sep 2022 06:22:45 +0000 (UTC) X-FDA: 79891553490.15.C431DEB Received: from conssluserg-05.nifty.com (conssluserg-05.nifty.com [210.131.2.90]) by imf27.hostedemail.com (Postfix) with SMTP id CA8BC400D5 for ; Fri, 9 Sep 2022 06:22:44 +0000 (UTC) Received: from mail-ot1-f53.google.com (mail-ot1-f53.google.com [209.85.210.53]) (authenticated) by conssluserg-05.nifty.com with ESMTP id 2896Mbns025803 for ; Fri, 9 Sep 2022 15:22:37 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-05.nifty.com 2896Mbns025803 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1662704558; bh=MYlsGWZEaj6riF53CJWpIUBe3dUwLTh06kCOuMwA78I=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=EmF3zkc3LNSyQbmWSHXGfk4e90+a8K9lM7qun/spg8Uv+kAInTvVhTw/sjDonAAJA xUw0VJKG2lOxoIpdR9vBUJhs6923AKBqB8h/m7RrKUlIUYUDUHf5uMOsN1SmKybUyA R1q2rsiAeqCImofKS5mh8sytxF42GLVvpIqT1oWvYJjiob2iyq9tCj+Fa5dHEGXQfE /itBstjrb9wcEqjRxldkiPS9qpx23RQeVng1seRrfW6x07iM5g8bcMtx+9+cEEaEJj w6dvkeuw2VVsRpUrpabG/pKZWsZlmMzoIy+BCLb0jxbAfEL6u3ubypS/y6/+Foo5Pi RR9GIKIJ4b9Pg== X-Nifty-SrcIP: [209.85.210.53] Received: by mail-ot1-f53.google.com with SMTP id l5-20020a05683004a500b0063707ff8244so469967otd.12 for ; Thu, 08 Sep 2022 23:22:37 -0700 (PDT) X-Gm-Message-State: ACgBeo0bA6z1LBVnhWjEg9EDsO1zOAGGzgSmgnEbHGQ3sl15L8g6Sg8f SMYMIBdAQLOw+cjP7ozqf/22vLzbFtsm1RDnpC4= X-Google-Smtp-Source: AA6agR6D+NvAoj+USNTBBy4mDLL9rmTs8LTzmXobal0BhXDFou2m+Sac50RiyG6CPG0cg/e8ofovoO8np947WoZjx2g= X-Received: by 2002:a9d:4806:0:b0:637:cdca:f8d3 with SMTP id c6-20020a9d4806000000b00637cdcaf8d3mr4944442otf.225.1662704556432; Thu, 08 Sep 2022 23:22:36 -0700 (PDT) MIME-Version: 1.0 References: <20220908104337.11940-1-lukas.bulwahn@gmail.com> <20220908104337.11940-3-lukas.bulwahn@gmail.com> In-Reply-To: <20220908104337.11940-3-lukas.bulwahn@gmail.com> From: Masahiro Yamada Date: Fri, 9 Sep 2022 15:22:00 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 2/6] x86: make config X86_FEATURE_NAMES visible with EXPERT To: Lukas Bulwahn Cc: Russell King , linux-arm-kernel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , X86 ML , Mauro Carvalho Chehab , Linux Media Mailing List , Peter Chen , Greg Kroah-Hartman , linux-usb , Andrew Morton , Mike Rapoport , Linux Memory Management List , Linux Kbuild mailing list , kernel-janitors@vger.kernel.org, Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662704565; a=rsa-sha256; cv=none; b=e3UCT4ENYuA+V9kLoTK0dH63CHQBe8PPRMgMEOKRztlxmAqM7NxYl+kRnz69x0x8uFbkFM IvVMwNJtO3hCb3IEmRurWEnOLWhSWY6iVLhi0I/k+ncYJgBI4s8jkp6szr8f2gw+ix9+hu S2i4OsqHwT5rfLoLZOjp16hUhlRm5fM= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=nifty.com header.s=dec2015msa header.b=EmF3zkc3; spf=softfail (imf27.hostedemail.com: 210.131.2.90 is neither permitted nor denied by domain of masahiroy@kernel.org) smtp.mailfrom=masahiroy@kernel.org; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=kernel.org (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662704565; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=MYlsGWZEaj6riF53CJWpIUBe3dUwLTh06kCOuMwA78I=; b=CJAtBWcUCKo71ct2iyJBFBmU1ezlk7aXHt3YUzDrI6cEpV4Yq+rL6KzvvFRst7bnNyepBb hQe2d6oOKIvGDqFImjaaWzH3JXh0vVD1stqUEEbMVgoCG1rRR1nHQuIu2fY+n0zMDQE4oN aDHdbcHCbgwZtye3kP+2frGFXAxMzvU= Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=nifty.com header.s=dec2015msa header.b=EmF3zkc3; spf=softfail (imf27.hostedemail.com: 210.131.2.90 is neither permitted nor denied by domain of masahiroy@kernel.org) smtp.mailfrom=masahiroy@kernel.org; dmarc=fail reason="No valid SPF, DKIM not aligned (relaxed)" header.from=kernel.org (policy=none) X-Rspam-User: X-Rspamd-Queue-Id: CA8BC400D5 X-Rspamd-Server: rspam09 X-Stat-Signature: dedfc8d6tw7hw1cgwayo647zu9xpabkm X-HE-Tag: 1662704564-558767 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Sep 8, 2022 at 7:43 PM Lukas Bulwahn wrote: > > Commit 6a108a14fa35 ("kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT") > introduces CONFIG_EXPERT to carry the previous intent of CONFIG_EMBEDDED > and just gives that intent a much better name. That has been clearly a good > and long overdue renaming, and it is clearly an improvement to the kernel > build configuration that has shown to help managing the kernel build > configuration in the last decade. > > However, rather than bravely and radically just deleting CONFIG_EMBEDDED, > this commit gives CONFIG_EMBEDDED a new intended semantics, but keeps it > open for future contributors to implement that intended semantics: > > A new CONFIG_EMBEDDED option is added that automatically selects > CONFIG_EXPERT when enabled and can be used in the future to isolate > options that should only be considered for embedded systems (RISC > architectures, SLOB, etc). > > Since then, this CONFIG_EMBEDDED implicitly had two purposes: > > - It can make even more options visible beyond what CONFIG_EXPERT makes > visible. In other words, it may introduce another level of enabling the > visibility of configuration options: always visible, visible with > CONFIG_EXPERT and visible with CONFIG_EMBEDDED. > > - Set certain default values of some configurations differently, > following the assumption that configuring a kernel build for an > embedded system generally starts with a different set of default values > compared to kernel builds for all other kind of systems. > > Considering the first purpose, at the point in time where CONFIG_EMBEDDED > was renamed to CONFIG_EXPERT, CONFIG_EXPERT already made 130 more options > become visible throughout all different menus for the kernel configuration. > Over the last decade, this has gradually increased, so that currently, with > CONFIG_EXPERT, roughly 170 more options become visible throughout all > different menus for the kernel configuration. In comparison, currently with > CONFIG_EMBEDDED enabled, just seven more options are visible, one in x86, > one in arm, and five for the ChipIdea Highspeed Dual Role Controller. > > As the numbers suggest, these two levels of enabling the visibility of even > more configuration options---beyond what CONFIG_EXPERT enables---never > evolved to a good solution in the last decade. In other words, this > additional level of visibility of configuration option with CONFIG_EMBEDDED > compared to CONFIG_EXPERT has since its introduction never become really > valuable. It requires quite some investigation to actually understand what > is additionally visible and it does not differ significantly in complexity > compared to just enabling CONFIG_EXPERT. This CONFIG_EMBEDDED---or any > other config to show more detailed options beyond CONFIG_EXPERT---is > unlikely to be valuable unless somebody puts significant effort in > identifying how such visibility options can be properly split and creating > clear criteria, when some config option is visible with CONFIG_EXPERT and > when some config option is visible only with some further option enabled > beyond CONFIG_EXPERT, such as CONFIG_EMBEDDED attempted to do. For now, it > is much more reasonable to simply make those additional seven options that > visible with CONFIG_EMBEDDED, visible with CONFIG_EXPERT, and then remove > CONFIG_EMBEDDED. If anyone spends significant effort in structuring the > visibility of config options, they may re-introduce suitable new config > options simply as they see fit. > > Make the config X86_FEATURE_NAMES visible when CONFIG_EXPERT is enabled. > > Signed-off-by: Lukas Bulwahn Reviewed-by: Masahiro Yamada > --- > arch/x86/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index 2ec0b1eabe86..7807eb1c8df8 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -438,7 +438,7 @@ config SMP > If you don't know what to do here, say N. > > config X86_FEATURE_NAMES > - bool "Processor feature human-readable names" if EMBEDDED > + bool "Processor feature human-readable names" if EXPERT > default y > help > This option compiles in a table of x86 feature bits and corresponding > -- > 2.17.1 > -- Best Regards Masahiro Yamada