From patchwork Wed Mar 3 10:20:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Tang X-Patchwork-Id: 12113225 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 A3216C433E0 for ; Wed, 3 Mar 2021 10:21:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2049C64EDF for ; Wed, 3 Mar 2021 10:21:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2049C64EDF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 765608D0145; Wed, 3 Mar 2021 05:21:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6C6B88D0135; Wed, 3 Mar 2021 05:21:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 569D68D0145; Wed, 3 Mar 2021 05:21:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id 228A68D0135 for ; Wed, 3 Mar 2021 05:21:08 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D9F548249980 for ; Wed, 3 Mar 2021 10:21:07 +0000 (UTC) X-FDA: 77878170174.20.76A4641 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by imf10.hostedemail.com (Postfix) with ESMTP id 0BAE5407F8EB for ; Wed, 3 Mar 2021 10:21:05 +0000 (UTC) IronPort-SDR: 69rLT1WOEfG2UX2U3wBEIinJiQ6+i/Ul+UiJO9Pfsak5RTR071bGqWqtVGfRiaooqYK25ar+oa mVFHPcEdoD+A== X-IronPort-AV: E=McAfee;i="6000,8403,9911"; a="272162724" X-IronPort-AV: E=Sophos;i="5.81,219,1610438400"; d="scan'208";a="272162724" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2021 02:21:06 -0800 IronPort-SDR: MRHzt/NdJJ8FWdsuRTptLifMQQnxpngh+dv2T5zzI55Qqxm9YUPoy+Wa2b3YLM0wgVbHYqkJcz 42YRkVq0arFQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,219,1610438400"; d="scan'208";a="445199976" Received: from shbuild999.sh.intel.com ([10.239.146.165]) by orsmga001.jf.intel.com with ESMTP; 03 Mar 2021 02:21:03 -0800 From: Feng Tang To: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton Cc: Michal Hocko , Andrea Arcangeli , David Rientjes , Mel Gorman , Mike Kravetz , Randy Dunlap , Vlastimil Babka , Dave Hansen , Ben Widawsky , Andi leen , Dan Williams , Feng Tang Subject: [PATCH v3 01/14] mm/mempolicy: Add comment for missing LOCAL Date: Wed, 3 Mar 2021 18:20:45 +0800 Message-Id: <1614766858-90344-2-git-send-email-feng.tang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1614766858-90344-1-git-send-email-feng.tang@intel.com> References: <1614766858-90344-1-git-send-email-feng.tang@intel.com> X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 0BAE5407F8EB X-Stat-Signature: 1c9ssm5s8ry8qjyry4pcrfokgqy5zzc6 Received-SPF: none (intel.com>: No applicable sender policy available) receiver=imf10; identity=mailfrom; envelope-from=""; helo=mga05.intel.com; client-ip=192.55.52.43 X-HE-DKIM-Result: none/none X-HE-Tag: 1614766865-285543 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: From: Ben Widawsky MPOL_LOCAL is a bit weird because it is simply a different name for an existing behavior (preferred policy with no node mask). It has been this way since it was added here: commit 479e2802d09f ("mm: mempolicy: Make MPOL_LOCAL a real policy") It is so similar to MPOL_PREFERRED in fact that when the policy is created in mpol_new, the mode is set as PREFERRED, and an internal state representing LOCAL doesn't exist. To prevent future explorers from scratching their head as to why MPOL_LOCAL isn't defined in the mpol_ops table, add a small comment explaining the situations. v2: Change comment to refer to mpol_new (Michal) Link: https://lore.kernel.org/r/20200630212517.308045-2-ben.widawsky@intel.com #Acked-by: Michal Hocko Signed-off-by: Ben Widawsky Signed-off-by: Feng Tang Acked-by: Michal Hocko --- mm/mempolicy.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 2c3a865..5730fc1 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -427,6 +427,7 @@ static const struct mempolicy_operations mpol_ops[MPOL_MAX] = { .create = mpol_new_bind, .rebind = mpol_rebind_nodemask, }, + /* [MPOL_LOCAL] - see mpol_new() */ }; static int migrate_page_add(struct page *page, struct list_head *pagelist,