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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 5F7DEC352A2 for ; Fri, 7 Feb 2020 13:17:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 34F06217BA for ; Fri, 7 Feb 2020 13:17:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581081454; bh=Wh+aHr1NwR/7KKHMurCrnVibPU11CvnUs69GsuGeCdY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=MYmcjgaQxD3xey+mBKFXdTB3/DdyEpwhW/jfRO9iuWC4ej8q7DLKt3QSWzds3AORp k/dr8kbGs+STVoRvjbe8W+VCcor3e5nBEYBlma5nKMUq/ACUQ9m2cR871Jr5Y56EuM 1dAqQt3Y649jgAOpysAEH+VxukpzxSc2I7HZV8wA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727123AbgBGNRd (ORCPT ); Fri, 7 Feb 2020 08:17:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:41292 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726674AbgBGNRd (ORCPT ); Fri, 7 Feb 2020 08:17:33 -0500 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D4A1921741; Fri, 7 Feb 2020 13:17:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581081452; bh=Wh+aHr1NwR/7KKHMurCrnVibPU11CvnUs69GsuGeCdY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jNHkG0Je9VOsZhBmi0gzPOvS79dhT9Y9WH+g7Bjv7dTp2Gya7FdUgsqCECKVOdJip M5PP18yP0bVCzAKk/aG0Rq5YQgQC0US4sGL3p46JFKAefPsL0HcAikpJEbvFUFi3n/ Plu8x3XLmVc59ikgo7h8NL/Zfs1FAPynvW0wrJBM= Date: Fri, 7 Feb 2020 22:17:28 +0900 From: Masami Hiramatsu To: Geert Uytterhoeven Cc: Borislav Petkov , Steven Rostedt , Linux Kernel Mailing List , Ingo Molnar , Andrew Morton Subject: Re: [for-next][PATCH 04/26] bootconfig: Add Extra Boot Config support Message-Id: <20200207221728.b79eecfe98b99bb4b2f4cc42@kernel.org> In-Reply-To: References: <20200114210316.450821675@goodmis.org> <20200114210336.259202220@goodmis.org> <20200206115405.GA22608@zn.tnic> <20200206234100.953b48ecef04f97c112d2e8b@kernel.org> <20200207093003.93711310cfafae98bb2a62f6@kernel.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Geert, On Fri, 7 Feb 2020 09:49:02 +0100 Geert Uytterhoeven wrote: > Hi Hiramatsu-san, > > On Fri, Feb 7, 2020 at 1:30 AM Masami Hiramatsu wrote: > > On Thu, 6 Feb 2020 18:20:15 +0100 > > Geert Uytterhoeven wrote: > > > On Thu, Feb 6, 2020 at 3:42 PM Masami Hiramatsu wrote: > > > > On Thu, 6 Feb 2020 12:54:05 +0100 > > > > Borislav Petkov wrote: > > > > > On Tue, Jan 14, 2020 at 04:03:20PM -0500, Steven Rostedt wrote: > > > > > > diff --git a/init/Kconfig b/init/Kconfig > > > > > > index a34064a031a5..63450d3bbf12 100644 > > > > > > --- a/init/Kconfig > > > > > > +++ b/init/Kconfig > > > > > > @@ -1215,6 +1215,17 @@ source "usr/Kconfig" > > > > > > > > > > > > endif > > > > > > > > > > > > +config BOOT_CONFIG > > > > > > + bool "Boot config support" > > > > > > + select LIBXBC > > > > > > + default y > > > > > > > > > > Any particular reason this is default y? Why should it be enabled by > > > > > default on all boxes? > > > > > > > > Oh, you are not the first person asked that :) > > > > > > > > https://lkml.org/lkml/2019/12/9/563 > > > > > > > > And yes, I think this is important that will useful for most developers > > > > and admins. Since the bootconfig already covers kernel and init options, > > > > this can be a new standard way to pass args to kernel boot. > > > > > > > > And as I reported above thread, the memory footpoint of view, most code > > > > and working memory are released after boot. Also, as Linus's suggested, > > > > now this feature is enabled only if user gives "bootconfig" on the kernel > > > > command line. So the side effect is minimized. > > > > > > With m68k/atari_defconfig, bloat-o-meter says: > > > > > > add/remove: 39/0 grow/shrink: 2/0 up/down: 13086/0 (13086) > > > > > > which is IMHO not that small for a "default y" option that may or may not > > > be used. > > > > > > Especially: > > > > > > Function old new delta > > > xbc_nodes - 8192 +8192 > > > > > > Any chance xbc_nodes can be allocated dynamically, and only when needed? > > > > Yes, I think we can use memblock to allocate it. However, this xbc_nodes is > > Good. > > > __init_data, which is released right after boot. So I think it should be > > OK except for your system doesn't have user space... > > __initdata is still part of the kernel image (note that we no longer > have __initbss) and consumes RAM early on, and is thus subject to e.g. > bootloader[1] and platform limitations (e.g. the kernel must fit in the > first block of physical memory). > So trying to avoid large static arrays is useful. OK, I'll replace it with memblock. Then it will be 5 - 6KB in total. Thank you! -- Masami Hiramatsu