From patchwork Tue Apr 14 11:32:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vlastimil Babka X-Patchwork-Id: 11487277 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EB14F92C for ; Tue, 14 Apr 2020 11:32:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B7F0B2072D for ; Tue, 14 Apr 2020 11:32:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7F0B2072D 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 614308E0001; Tue, 14 Apr 2020 07:32:31 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 262828E000B; Tue, 14 Apr 2020 07:32:31 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EE0328E0006; Tue, 14 Apr 2020 07:32:30 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0065.hostedemail.com [216.40.44.65]) by kanga.kvack.org (Postfix) with ESMTP id C07808E0005 for ; Tue, 14 Apr 2020 07:32:30 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 7A1DC52AD for ; Tue, 14 Apr 2020 11:32:30 +0000 (UTC) X-FDA: 76706247660.10.tray02_8a3f182290817 X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,vbabka@suse.cz,,RULES_HIT:30036:30054:30056:30062:30070,0,RBL:195.135.220.15:@suse.cz:.lbl8.mailshell.net-64.100.201.201 62.2.6.2,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: tray02_8a3f182290817 X-Filterd-Recvd-Size: 3834 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Tue, 14 Apr 2020 11:32:29 +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 0FBFBADB5; Tue, 14 Apr 2020 11:32:27 +0000 (UTC) From: Vlastimil Babka To: Andrew Morton , 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 , Masami Hiramatsu , Vlastimil Babka Subject: [PATCH v2 0/3] support setting sysctl parameters from kernel command line Date: Tue, 14 Apr 2020 13:32:19 +0200 Message-Id: <20200414113222.16959-1-vbabka@suse.cz> X-Mailer: git-send-email 2.26.0 MIME-Version: 1.0 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 parameters via kernel command line options in the form of sysctl.vm.something=1 The important part is Patch 1. The second, not so important part is an attempt 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 with generic sysctl support the idea is to remove the one-off param handlers and 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 but warn on deprecated value these days. - hung_task_panic is converted in Patch 3, but there's a downside that now 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 pointless for a single flag 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 Changes since v1: - add missing newlines on printk's - more adjustments to proc mount param passing (Kees) - rebase to 5.7-rc1 - add acks/reviews - test driver (how to pass a testing boot parameter without bootloader specific steps) still under discussion - new Kconfig? bootconfig? .../admin-guide/kernel-parameters.txt | 11 +- fs/proc/proc_sysctl.c | 142 ++++++++++++++++++ include/linux/sysctl.h | 4 + init/main.c | 2 + kernel/hung_task.c | 10 -- mm/page_alloc.c | 9 -- 6 files changed, 158 insertions(+), 20 deletions(-) Acked-by: Michal Hocko