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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 D3F3BC54FD0 for ; Wed, 25 Mar 2020 12:03:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A3DB020771 for ; Wed, 25 Mar 2020 12:03:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A3DB020771 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 441AC6B000C; Wed, 25 Mar 2020 08:03:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3F1926B000D; Wed, 25 Mar 2020 08:03:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 32E666B000E; Wed, 25 Mar 2020 08:03:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0165.hostedemail.com [216.40.44.165]) by kanga.kvack.org (Postfix) with ESMTP id 185B16B000C for ; Wed, 25 Mar 2020 08:03:57 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D3B8A180AD80F for ; Wed, 25 Mar 2020 12:03:56 +0000 (UTC) X-FDA: 76633750872.14.pear48_79b5aea28a229 X-HE-Tag: pear48_79b5aea28a229 X-Filterd-Recvd-Size: 4231 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Wed, 25 Mar 2020 12:03:56 +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 55912AC37; Wed, 25 Mar 2020 12:03:54 +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" , Vlastimil Babka Subject: [RFC v2 2/2] kernel/sysctl: support handling command line aliases Date: Wed, 25 Mar 2020 13:03:45 +0100 Message-Id: <20200325120345.12946-2-vbabka@suse.cz> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200325120345.12946-1-vbabka@suse.cz> References: <20200325120345.12946-1-vbabka@suse.cz> 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: We can now handle sysctl parameters on kernel command line, but historica= lly some parameters introduced their own command line equivalent, which we do= n't want to remove for compatibility reasons. We can however convert them to = the generic infrastructure with a table translating the legacy command line parameters to their sysctl names, and removing the one-off param handlers= . This patch adds the support and makes the first conversion to demonstrate= it, on the (deprecated) numa_zonelist_order parameter. Signed-off-by: Vlastimil Babka --- kernel/sysctl.c | 39 +++++++++++++++++++++++++++++++++++---- mm/page_alloc.c | 9 --------- 2 files changed, 35 insertions(+), 13 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 18c7f5606d55..fd72853396f9 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1971,6 +1971,22 @@ static struct ctl_table dev_table[] =3D { { } }; =20 +struct sysctl_alias { + char *kernel_param; + char *sysctl_param; +}; + +/* + * Historically some settings had both sysctl and a command line paramet= er. + * With the generic sysctl. parameter support, we can handle them at a s= ingle + * place and only keep the historical name for compatibility. This is no= t meant + * to add brand new aliases. + */ +static struct sysctl_alias sysctl_aliases[] =3D { + {"numa_zonelist_order", "vm.numa_zonelist_order" }, + { } +}; + int __init sysctl_init(void) { struct ctl_table_header *hdr; @@ -1980,6 +1996,18 @@ int __init sysctl_init(void) return 0; } =20 +char *sysctl_find_alias(char *param) +{ + struct sysctl_alias *alias; + + for (alias =3D &sysctl_aliases[0]; alias->kernel_param !=3D NULL; alias= ++) { + if (strcmp(alias->kernel_param, param) =3D=3D 0) + return alias->sysctl_param; + } + + return NULL; +} + /* Set sysctl value passed on kernel command line. */ int process_sysctl_arg(char *param, char *val, const char *unused, void *arg) @@ -1990,10 +2018,13 @@ int process_sysctl_arg(char *param, char *val, loff_t ppos =3D 0; struct ctl_table *ctl, *found =3D NULL; =20 - if (strncmp(param, "sysctl.", sizeof("sysctl.") - 1)) - return 0; - - param +=3D sizeof("sysctl.") - 1; + if (strncmp(param, "sysctl.", sizeof("sysctl.") - 1) =3D=3D 0) { + param +=3D sizeof("sysctl.") - 1; + } else { + param =3D sysctl_find_alias(param); + if (!param) + return 0; + } =20 remaining =3D param; ctl =3D &sysctl_base_table[0]; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3c4eb750a199..de7a134b1b8a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5460,15 +5460,6 @@ static int __parse_numa_zonelist_order(char *s) return 0; } =20 -static __init int setup_numa_zonelist_order(char *s) -{ - if (!s) - return 0; - - return __parse_numa_zonelist_order(s); -} -early_param("numa_zonelist_order", setup_numa_zonelist_order); - char numa_zonelist_order[] =3D "Node"; =20 /* --=20 2.25.1