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=-9.7 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 616E3C2D0E5 for ; Thu, 26 Mar 2020 18:16:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2FC872076A for ; Thu, 26 Mar 2020 18:16:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2FC872076A 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 B9A706B0008; Thu, 26 Mar 2020 14:16:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B57AD6B0032; Thu, 26 Mar 2020 14:16:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9C47C6B0010; Thu, 26 Mar 2020 14:16:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0208.hostedemail.com [216.40.44.208]) by kanga.kvack.org (Postfix) with ESMTP id 804896B0008 for ; Thu, 26 Mar 2020 14:16:25 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id B90978248047 for ; Thu, 26 Mar 2020 18:16:25 +0000 (UTC) X-FDA: 76638318330.10.shoe42_552d014c70f3f X-HE-Tag: shoe42_552d014c70f3f X-Filterd-Recvd-Size: 4667 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Thu, 26 Mar 2020 18:16:25 +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 D7D36ADE2; Thu, 26 Mar 2020 18:16:22 +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 v3 2/2] kernel/sysctl: support handling command line aliases Date: Thu, 26 Mar 2020 19:16:06 +0100 Message-Id: <20200326181606.7027-2-vbabka@suse.cz> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200326181606.7027-1-vbabka@suse.cz> References: <20200326181606.7027-1-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 --- Changes in v3: - constify some things according to Kees - expand the comment of sysctl_aliases to note on different timings fs/proc/proc_sysctl.c | 48 ++++++++++++++++++++++++++++++++++++------- mm/page_alloc.c | 9 -------- 2 files changed, 41 insertions(+), 16 deletions(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 8ee3273e4540..3a861e0a7c7e 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -1729,6 +1729,37 @@ int __init proc_sys_init(void) =20 struct vfsmount *proc_mnt =3D NULL; =20 +struct sysctl_alias { + const char *kernel_param; + const 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. When adding existing aliases, consider whet= her + * the possibly different moment of changing the value (e.g. from early_= param + * to the moment do_sysctl_args() is called) is an issue for the specifi= c + * parameter. + */ +static const struct sysctl_alias sysctl_aliases[] =3D { + {"numa_zonelist_order", "vm.numa_zonelist_order" }, + { } +}; + +const char *sysctl_find_alias(char *param) +{ + const 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. */ static int process_sysctl_arg(char *param, char *val, const char *unused, void *arg) @@ -1741,15 +1772,18 @@ static int process_sysctl_arg(char *param, char *= val, loff_t pos =3D 0; ssize_t wret; =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; =20 - if (param[0] !=3D '/' && param[0] !=3D '.') - return 0; + if (param[0] !=3D '/' && param[0] !=3D '.') + return 0; =20 - param++; + param++; + } else { + param =3D (char *) sysctl_find_alias(param); + if (!param) + return 0; + } =20 if (!proc_mnt) { proc_fs_type =3D get_fs_type("proc"); 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