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 3703FC54EBD for ; Tue, 10 Jan 2023 01:10:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230174AbjAJBKB (ORCPT ); Mon, 9 Jan 2023 20:10:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229991AbjAJBJ6 (ORCPT ); Mon, 9 Jan 2023 20:09:58 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05508B0E; Mon, 9 Jan 2023 17:09:57 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9845AB80883; Tue, 10 Jan 2023 01:09:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33AA2C433EF; Tue, 10 Jan 2023 01:09:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673312994; bh=WGQHRqujxAp25OFY1BaFnKnf/OBWaVYYjw1u/l84xG8=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=ElgUeVqsoKXmcPyBKcGMzezri38h3StmSw3QHTXFeIVJsVD98KGFUfpK/zz/A0plF Bvj9tJThV0kInRMnfL9oofLLyfTC8Tl8ldpuONgueATGdSPnrV+FB1kIXSZi60GuWA cgST5fg1SCwMvb33FIPl/IuIOebWbDF4ApaOBN7xxmLoQP6f/NPr+BiH5iFId7WSen W7KeNOeqGRlgv6JhWtJzzrg2BzzMIiTeb3lD55sS13ZE3YiEg96UPYkyG81HAS2lOe 2W82majnoXu/lZMICkg0rGm0G1Ag7ofQfJYXhxCubF/jBqvm/vKwxJXESLVKoMv0au BnYWh5lu62cUg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id C8D645C0623; Mon, 9 Jan 2023 17:09:53 -0800 (PST) Date: Mon, 9 Jan 2023 17:09:53 -0800 From: "Paul E. McKenney" To: Masami Hiramatsu Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, corbet@lwn.net, akpm@linux-foundation.org, ndesaulniers@google.com, vbabka@suse.cz, hannes@cmpxchg.org, joel@joelfernandes.org, quic_neeraju@quicinc.com, urezki@gmail.com Subject: Re: [PATCH RFC bootconfig] Allow forcing unconditional bootconfig processing Message-ID: <20230110010953.GF4028633@paulmck-ThinkPad-P17-Gen-1> Reply-To: paulmck@kernel.org References: <20230105005838.GA1772817@paulmck-ThinkPad-P17-Gen-1> <20230108002215.c18df95b19acdd3207b379fa@kernel.org> <20230107162202.GA4028633@paulmck-ThinkPad-P17-Gen-1> <20230108150425.426f2861e9db1152fa84508f@kernel.org> <20230109042501.GF4028633@paulmck-ThinkPad-P17-Gen-1> <20230110085636.5d679f98c5b6914ecf19e724@kernel.org> <20230110000732.GD4028633@paulmck-ThinkPad-P17-Gen-1> <20230110095450.2cb4c875f95459e3a4e7dcf1@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230110095450.2cb4c875f95459e3a4e7dcf1@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 10, 2023 at 09:54:50AM +0900, Masami Hiramatsu wrote: > On Mon, 9 Jan 2023 16:07:32 -0800 > "Paul E. McKenney" wrote: > > > On Tue, Jan 10, 2023 at 08:56:36AM +0900, Masami Hiramatsu wrote: > > > On Sun, 8 Jan 2023 20:25:01 -0800 > > > "Paul E. McKenney" wrote: > > > > > > > On Sun, Jan 08, 2023 at 03:04:25PM +0900, Masami Hiramatsu wrote: > > > > > On Sat, 7 Jan 2023 08:22:02 -0800 > > > > > "Paul E. McKenney" wrote: > > > > > > > > > > > On Sun, Jan 08, 2023 at 12:22:15AM +0900, Masami Hiramatsu wrote: > > > > > > > On Wed, 4 Jan 2023 16:58:38 -0800 > > > > > > > "Paul E. McKenney" wrote: > > > > > > > > > > > > > > > The BOOT_CONFIG family of Kconfig options allows a bootconfig file > > > > > > > > containing kernel boot parameters to be embedded into an initrd or into > > > > > > > > the kernel itself. This can be extremely useful when deploying kernels > > > > > > > > in cases where some of the boot parameters depend on the kernel version > > > > > > > > rather than on the server hardware, firmware, or workload. > > > > > > > > > > > > > > > > Unfortunately, the "bootconfig" kernel parameter must be specified in > > > > > > > > order to cause the kernel to look for the embedded bootconfig file, > > > > > > > > and it clearly does not help to embed this "bootconfig" kernel parameter > > > > > > > > into that file. > > > > > > > > > > > > > > > > Therefore, provide a new BOOT_CONFIG_FORCE Kconfig option that causes the > > > > > > > > kernel to act as if the "bootconfig" kernel parameter had been specified. > > > > > > > > In other words, kernels built with CONFIG_BOOT_CONFIG_FORCE=y will look > > > > > > > > for the embedded bootconfig file even when the "bootconfig" kernel > > > > > > > > parameter is omitted. This permits kernel-version-dependent kernel > > > > > > > > boot parameters to be embedded into the kernel image without the need to > > > > > > > > (for example) update large numbers of boot loaders. > > > > > > > > > > > > > > I like this because this is a simple solution. We have another option > > > > > > > to specify "bootconfig" in CONFIG_CMDLINE, but it can be overwritten by > > > > > > > bootloader. Thus, it is better to have this option so that user can > > > > > > > always enable bootconfig. > > > > > > > > > > > > Glad you like it! > > > > > > > > > > > > In addition, if the help text is accurate, another shortcoming of > > > > > > CONFIG_CMDLINE is that its semantics vary from one architecture to > > > > > > another. Some have CONFIG_CMDLINE override the boot-loader supplied > > > > > > parameters, and others differ in the order in which the parameters > > > > > > are processed. > > > > > > > > > > Yes, that differences confuse us... > > > > > > > > I am glad that it is not just me. ;-) > > > > > > > > I will add words to that effect to the commit log. > > > > > > > > > > > Acked-by: Masami Hiramatsu (Google) > > > > > > > > > > > > Thank you! > > > > > > > > > > > > > BTW, maybe CONFIG_BOOT_CONFIG_EMBED is better to select this. > > > > > > > (or at least recommend to enable this) > > > > > > > > > > > > Like this? > > > > > > > > > > Yes! Thanks. > > > > > > > > > > > > > > > > > Thanx, Paul > > > > > > > > > > > > ------------------------------------------------------------------------ > > > > > > > > > > > > commit d09a1505c51a70da38b34ac38062977299aef742 > > > > > > Author: Paul E. McKenney > > > > > > Date: Sat Jan 7 08:09:22 2023 -0800 > > > > > > > > > > > > bootconfig: Default BOOT_CONFIG_FORCE to y if BOOT_CONFIG_EMBED > > > > > > > > > > > > When a kernel is built with CONFIG_BOOT_CONFIG_EMBED=y, the intention > > > > > > will normally be to unconditionally provide the specified kernel-boot > > > > > > arguments to the kernel, as opposed to requiring a separately provided > > > > > > bootconfig parameter. Therefore, make the BOOT_CONFIG_FORCE Kconfig > > > > > > option default to y in kernels built with CONFIG_BOOT_CONFIG_EMBED=y. > > > > > > > > > > > > The old semantics may be obtained by manually overriding this default. > > > > > > > > > > > > Suggested-by: Masami Hiramatsu > > > > > > Signed-off-by: Paul E. McKenney > > > > > > > > > > Acked-by: Masami Hiramatsu (Google) > > > > > > > > Applied, thank you! > > > > > > Paul, just for confirmation, have you picked these patches on your tree? > > > > I have, but if you would prefer to take them, just let me know when you > > have pulled them in. It is easy for me to drop them. > > > > Here they are in the -rcu tree: > > > > 3d9ccc4a8b56e bootconfig: Allow forcing unconditional bootconfig processing > > 68b920592ff67 bootconfig: Default BOOT_CONFIG_FORCE to y if BOOT_CONFIG_EMBED > > > > git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > > Yeah, if it's not hurry, let me pick those to linux-trace tree > (bootconfig/for-next). I would like to consolidate the bootconfig > updates on my tree. Please go ahead and grab them. Just out of curiosity, are they in time for the upcoming v6.3 merge window? Thanx, Paul > Thanks, > > > > > Thanx, Paul > > > > > Thank you, > > > > > > > > > > > > Thank you! > > > > > > > > > > > > > > > > > diff --git a/init/Kconfig b/init/Kconfig > > > > > > index 0fb19fa0edba9..97a0f14d9020d 100644 > > > > > > --- a/init/Kconfig > > > > > > +++ b/init/Kconfig > > > > > > @@ -1379,6 +1379,7 @@ config BOOT_CONFIG > > > > > > config BOOT_CONFIG_FORCE > > > > > > bool "Force unconditional bootconfig processing" > > > > > > depends on BOOT_CONFIG > > > > > > + default y if BOOT_CONFIG_EMBED > > > > > > help > > > > > > With this Kconfig option set, BOOT_CONFIG processing is carried > > > > > > out even when the "bootconfig" kernel-boot parameter is omitted. > > > > > > > > > > > > > > > -- > > > > > Masami Hiramatsu (Google) > > > > > > > > > -- > > > Masami Hiramatsu (Google) > > > -- > Masami Hiramatsu (Google)