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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 495C5C2D0ED for ; Mon, 30 Mar 2020 11:55:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 18DD620578 for ; Mon, 30 Mar 2020 11:55:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 18DD620578 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 970276B000C; Mon, 30 Mar 2020 07:55:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8D0C46B006C; Mon, 30 Mar 2020 07:55:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 77C6A6B0037; Mon, 30 Mar 2020 07:55:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0042.hostedemail.com [216.40.44.42]) by kanga.kvack.org (Postfix) with ESMTP id 5F4E86B0008 for ; Mon, 30 Mar 2020 07:55:55 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 3801E180AD801 for ; Mon, 30 Mar 2020 11:55:55 +0000 (UTC) X-FDA: 76651874670.19.house57_33a051799e709 X-HE-Tag: house57_33a051799e709 X-Filterd-Recvd-Size: 3781 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf24.hostedemail.com (Postfix) with ESMTP for ; Mon, 30 Mar 2020 11:55:54 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id A8C2DAD11; Mon, 30 Mar 2020 11:55:52 +0000 (UTC) From: Vlastimil Babka To: Luis Chamberlain , Kees Cook , Iurii Zaikin Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-mm@kvack.org, Ivan Teterevkov , Michal Hocko , David Rientjes , Matthew Wilcox , "Eric W . Biederman" , "Guilherme G . Piccoli" , Alexey Dobriyan , Thomas Gleixner , Greg Kroah-Hartman , Christian Brauner , Vlastimil Babka Subject: [PATCH 0/3] support setting sysctl parameters from kernel command line Date: Mon, 30 Mar 2020 13:55:32 +0200 Message-Id: <20200330115535.3215-1-vbabka@suse.cz> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: This series adds support for something that seems like many people always wanted but nobody added it yet, so here's the ability to set sysctl param= eters via kernel command line options in the form of sysctl.vm.something=3D1 The important part is Patch 1. The second, not so important part is an at= tempt to clean up legacy one-off parameters that do the same thing as a sysctl. I don't want to remove them completely for compatibility reasons, but wit= h generic sysctl support the idea is to remove the one-off param handlers a= nd treat the parameters as aliases for the sysctl variants. I have identified several parameters that mention sysctl counterparts in Documentation/admin-guide/kernel-parameters.txt but there might be more. = The conversion also has varying level of success: - numa_zonelist_order is converted in Patch 2 together with adding the necessary infrastructure. It's easy as it doesn't really do anything bu= t warn on deprecated value these days. - hung_task_panic is converted in Patch 3, but there's a downside that no= w it only accepts 0 and 1, while previously it was any integer value - nmi_watchdog maps to two sysctls nmi_watchdog and hardlockup_panic, so there's no straighforward conversion possible - traceoff_on_warning is a flag without value and it would be required to handle that somehow in the conversion infractructure, which seems point= less for a single flag Anyway I hope that Patch 1 is mature enough to go regardless of the fate = of the less important second part. Changes since RFCv2 - make proc_mnt internal to functions (Kees) - use kasprintf when building path (Kees) - improve error reporting - common errnos are translated to more obvious messages and the rest uses %pe Vlastimil Babka (3): kernel/sysctl: support setting sysctl parameters from kernel command line kernel/sysctl: support handling command line aliases kernel/hung_task convert hung_task_panic boot parameter to sysctl .../admin-guide/kernel-parameters.txt | 11 +- fs/proc/proc_sysctl.c | 135 ++++++++++++++++++ include/linux/sysctl.h | 4 + init/main.c | 2 + kernel/hung_task.c | 10 -- mm/page_alloc.c | 9 -- 6 files changed, 151 insertions(+), 20 deletions(-) --=20 2.25.1