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 E7281C81980 for ; Mon, 27 Apr 2020 18:04:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B4151214D8 for ; Mon, 27 Apr 2020 18:04:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4151214D8 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 548E08E0007; Mon, 27 Apr 2020 14:04:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3C2008E000A; Mon, 27 Apr 2020 14:04:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 126748E0006; Mon, 27 Apr 2020 14:04:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0102.hostedemail.com [216.40.44.102]) by kanga.kvack.org (Postfix) with ESMTP id AE8BA8E0006 for ; Mon, 27 Apr 2020 14:04:51 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 629794DCF for ; Mon, 27 Apr 2020 18:04:51 +0000 (UTC) X-FDA: 76754410782.08.roll67_64870f3148e36 X-HE-Tag: roll67_64870f3148e36 X-Filterd-Recvd-Size: 4504 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Mon, 27 Apr 2020 18:04:50 +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 EDA14ACC4; Mon, 27 Apr 2020 18:04:47 +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 v3 0/5] support setting sysctl parameters from kernel command line Date: Mon, 27 Apr 2020 20:04:28 +0200 Message-Id: <20200427180433.7029-1-vbabka@suse.cz> X-Mailer: git-send-email 2.26.0 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 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 v2: - rebase to 5.7-rc3 - add acks - add a testcase to tools/testing/selftests/sysctl/sysctl.sh - this adds = a new sysctl parameter ../boot_int in lib/test_sysctl and expects the tester = to pass the respective boot parameter in any feasible way (including bootc= onfig) the testcase checks /proc/cmdline to distinguish real failure from the = lack of parameter. That allows us to test this without introducing further new functionality (patches 4+5). Vlastimil Babka (5): 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 tools/testing/selftests/sysctl/sysctl.sh: support CONFIG_TEST_SYSCTL=3D= y lib/test_sysctl: support testing of sysctl. boot parameter .../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 -- lib/test_sysctl.c | 13 ++ mm/page_alloc.c | 9 -- tools/testing/selftests/sysctl/sysctl.sh | 42 +++++- 8 files changed, 210 insertions(+), 23 deletions(-) --=20 2.26.0