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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B779ECAAD3 for ; Fri, 9 Sep 2022 06:31:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231213AbiIIGbW (ORCPT ); Fri, 9 Sep 2022 02:31:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231131AbiIIGbM (ORCPT ); Fri, 9 Sep 2022 02:31:12 -0400 Received: from condef-02.nifty.com (condef-02.nifty.com [202.248.20.67]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E64C3F0289; Thu, 8 Sep 2022 23:31:09 -0700 (PDT) Received: from conssluserg-03.nifty.com ([10.126.8.82])by condef-02.nifty.com with ESMTP id 2896PLmq003944; Fri, 9 Sep 2022 15:25:21 +0900 Received: from mail-oa1-f42.google.com (mail-oa1-f42.google.com [209.85.160.42]) (authenticated) by conssluserg-03.nifty.com with ESMTP id 2896Otxx016731; Fri, 9 Sep 2022 15:24:56 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-03.nifty.com 2896Otxx016731 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1662704696; bh=7NjVtVy//nlbx9x3Pt5ijYazqoLxIT1B+J2u/cAaj5Q=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=KaFtlN+jzzJHMJL7c8FlP3XnT2MXGlN9MN3qKNXeuVsKp446gcsOJv9z4a+ybaOmB OlhaK0CsiSKB0kA7ZAto9iF/oIf7KX7lgF97kID7F2pP6njvRlaSud7i9Vb9zsFGa9 veemIoSD/Rg4KipRuU4apgs5oIFnTpCzTrJTNHJxmobqqXttLfN1zc6XU/3uawal4q 155fKL5LmrGfd131UnybC6I2MS+65fjIrCjjsAy7f/x2xgjV7tRpJoTfLqMgJ7priv x20/MBLp8EzPvOmlnLaJF1mpMqqSz7oeHQFrW6NlQkKs1vWm5L1/m84CDLAl9BhImh nRlaRcf9BZeUQ== X-Nifty-SrcIP: [209.85.160.42] Received: by mail-oa1-f42.google.com with SMTP id 586e51a60fabf-1225219ee46so1563400fac.2; Thu, 08 Sep 2022 23:24:56 -0700 (PDT) X-Gm-Message-State: ACgBeo2x3Mz0Gix4lRa9CirddqtGJIK88sL7DJlQR7SzX5RmmHMN5VnQ +irFiAgiq+LE6vAv+dtyZe+uyGKbP1maYiKIeoE= X-Google-Smtp-Source: AA6agR68HxJp7Gt5/W9hJjJn1oNwjlIoYy1BfzwQ+ek2/Aphzioca6ZO3YEOgn/MHLAPX31bHXbrpRG4YXb9tNqZENw= X-Received: by 2002:a05:6808:1b85:b0:34d:8ce1:d5b0 with SMTP id cj5-20020a0568081b8500b0034d8ce1d5b0mr1415326oib.194.1662704695320; Thu, 08 Sep 2022 23:24:55 -0700 (PDT) MIME-Version: 1.0 References: <20220908104337.11940-1-lukas.bulwahn@gmail.com> <20220908104337.11940-7-lukas.bulwahn@gmail.com> In-Reply-To: <20220908104337.11940-7-lukas.bulwahn@gmail.com> From: Masahiro Yamada Date: Fri, 9 Sep 2022 15:24:19 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 6/6] init/Kconfig: remove confusing config EMBEDDED 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" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 8, 2022 at 7:44 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. > > Hence, all uses of CONFIG_EMBEDDED have been replaced with CONFIG_EXPERT. > > Considering the second purpose, note that already probably arguing that a > kernel build for an embedded system would choose some values differently is > already tricky: the set of embedded systems with Linux kernels is already > quite diverse. Many embedded system have powerful CPUs and it would not be > clear that all embedded systems just optimize towards one specific aspect, > e.g., a smaller kernel image size. So, it is unclear if starting with "one > set of default configuration" that is induced by CONFIG_EMBEDDED is a good > offer for developers configuring their kernels. > > Also, the differences of needed user-space features in an embedded system > compared to a non-embedded system are probably difficult or even impossible > to name in some generic way. > > So it is not surprising that in the last decade hardly anyone has > contributed changes to make something default differently in case of > CONFIG_EMBEDDED=y. > > In v6.0-rc4, SECRETMEM is the only config switched off if > CONFIG_EMBEDDED=y. That one use was removed as well, SECRETMEM was made > configurable at build time by experts using menuconfig instead. > > As there are no further uses of CONFIG_EMBEDDED and CONFIG_EMBEDDED never > lived up to its intended purpose defined above, simply delete this > confusing CONFIG_EMBEDDED. > > Signed-off-by: Lukas Bulwahn > --- > init/Kconfig | 8 -------- > 1 file changed, 8 deletions(-) > > diff --git a/init/Kconfig b/init/Kconfig > index 9e3fd79b089c..d7429e0b8cae 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1818,14 +1818,6 @@ config DEBUG_RSEQ > > If unsure, say N. > > -config EMBEDDED > - bool "Embedded system" > - select EXPERT > - help > - This option should be enabled if compiling the kernel for > - an embedded system so certain expert options are available > - for configuration. > - > config HAVE_PERF_EVENTS > bool > help > -- > 2.17.1 > So, I am supposed to pick this up after 01-05 land. (please ping me if I forget about it). For now, Reviewed-by: Masahiro Yamada -- Best Regards Masahiro Yamada 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 42882ECAAD3 for ; Fri, 9 Sep 2022 06:27:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6PD60eyNrZy1Z6LjyUTBlIkV01Hd49DypwdK0nT6NII=; b=EOUUtj1ig22rvw nEFiGITIqkHPnNTWy2yNNnE1Swsqg7nDPHAxTZaKmJMjZTyssZaGZofi7fr6EmO8YA5+hoXc7a5Et W/N9BK3vcTiMMHZZtHilI9F9vVZxSnKsx4Hp7xMLq6g0YEIXnhDTt02GsjiXIYPdtbmTGUe6X5s1n i6KUnm/BkJVzGAtDE8xxln9OdRfeFJDjk4UBRPFoW0nObPcr1x0B0ihhX9UV2uJ7Z2IRjY4uJVn0T aAqwQvZDLblZUEH+Eks6jUT1aieOnfl/Xd2iiGtiLPcDPt5Jlc046WhMVR82LhvacVn2ljREj9Pz+ W2odeEvgsHoMZCHHy3iQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oWXSv-00DHsM-PR; Fri, 09 Sep 2022 06:26:14 +0000 Received: from conssluserg-05.nifty.com ([210.131.2.90]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oWXRv-00DHBr-0l for linux-arm-kernel@lists.infradead.org; Fri, 09 Sep 2022 06:25:13 +0000 Received: from mail-oa1-f52.google.com (mail-oa1-f52.google.com [209.85.160.52]) (authenticated) by conssluserg-05.nifty.com with ESMTP id 2896OtrX027607 for ; Fri, 9 Sep 2022 15:24:56 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-05.nifty.com 2896OtrX027607 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1662704696; bh=7NjVtVy//nlbx9x3Pt5ijYazqoLxIT1B+J2u/cAaj5Q=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=KaFtlN+jzzJHMJL7c8FlP3XnT2MXGlN9MN3qKNXeuVsKp446gcsOJv9z4a+ybaOmB OlhaK0CsiSKB0kA7ZAto9iF/oIf7KX7lgF97kID7F2pP6njvRlaSud7i9Vb9zsFGa9 veemIoSD/Rg4KipRuU4apgs5oIFnTpCzTrJTNHJxmobqqXttLfN1zc6XU/3uawal4q 155fKL5LmrGfd131UnybC6I2MS+65fjIrCjjsAy7f/x2xgjV7tRpJoTfLqMgJ7priv x20/MBLp8EzPvOmlnLaJF1mpMqqSz7oeHQFrW6NlQkKs1vWm5L1/m84CDLAl9BhImh nRlaRcf9BZeUQ== X-Nifty-SrcIP: [209.85.160.52] Received: by mail-oa1-f52.google.com with SMTP id 586e51a60fabf-11eab59db71so1485321fac.11 for ; Thu, 08 Sep 2022 23:24:56 -0700 (PDT) X-Gm-Message-State: ACgBeo1bIOu4bSdEWpPQcebbUAag1E57XSxd6/oQfS8DXSddTLBXjEco cRLiWjsNmS5V3nNQTauN1HiEaK2nd1saTsTnMyQ= X-Google-Smtp-Source: AA6agR68HxJp7Gt5/W9hJjJn1oNwjlIoYy1BfzwQ+ek2/Aphzioca6ZO3YEOgn/MHLAPX31bHXbrpRG4YXb9tNqZENw= X-Received: by 2002:a05:6808:1b85:b0:34d:8ce1:d5b0 with SMTP id cj5-20020a0568081b8500b0034d8ce1d5b0mr1415326oib.194.1662704695320; Thu, 08 Sep 2022 23:24:55 -0700 (PDT) MIME-Version: 1.0 References: <20220908104337.11940-1-lukas.bulwahn@gmail.com> <20220908104337.11940-7-lukas.bulwahn@gmail.com> In-Reply-To: <20220908104337.11940-7-lukas.bulwahn@gmail.com> From: Masahiro Yamada Date: Fri, 9 Sep 2022 15:24:19 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 6/6] init/Kconfig: remove confusing config EMBEDDED 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220908_232511_313717_929D633B X-CRM114-Status: GOOD ( 44.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Sep 8, 2022 at 7:44 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. > > Hence, all uses of CONFIG_EMBEDDED have been replaced with CONFIG_EXPERT. > > Considering the second purpose, note that already probably arguing that a > kernel build for an embedded system would choose some values differently is > already tricky: the set of embedded systems with Linux kernels is already > quite diverse. Many embedded system have powerful CPUs and it would not be > clear that all embedded systems just optimize towards one specific aspect, > e.g., a smaller kernel image size. So, it is unclear if starting with "one > set of default configuration" that is induced by CONFIG_EMBEDDED is a good > offer for developers configuring their kernels. > > Also, the differences of needed user-space features in an embedded system > compared to a non-embedded system are probably difficult or even impossible > to name in some generic way. > > So it is not surprising that in the last decade hardly anyone has > contributed changes to make something default differently in case of > CONFIG_EMBEDDED=y. > > In v6.0-rc4, SECRETMEM is the only config switched off if > CONFIG_EMBEDDED=y. That one use was removed as well, SECRETMEM was made > configurable at build time by experts using menuconfig instead. > > As there are no further uses of CONFIG_EMBEDDED and CONFIG_EMBEDDED never > lived up to its intended purpose defined above, simply delete this > confusing CONFIG_EMBEDDED. > > Signed-off-by: Lukas Bulwahn > --- > init/Kconfig | 8 -------- > 1 file changed, 8 deletions(-) > > diff --git a/init/Kconfig b/init/Kconfig > index 9e3fd79b089c..d7429e0b8cae 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -1818,14 +1818,6 @@ config DEBUG_RSEQ > > If unsure, say N. > > -config EMBEDDED > - bool "Embedded system" > - select EXPERT > - help > - This option should be enabled if compiling the kernel for > - an embedded system so certain expert options are available > - for configuration. > - > config HAVE_PERF_EVENTS > bool > help > -- > 2.17.1 > So, I am supposed to pick this up after 01-05 land. (please ping me if I forget about it). For now, Reviewed-by: Masahiro Yamada -- Best Regards Masahiro Yamada _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel