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=-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 102D5C433DB for ; Wed, 17 Mar 2021 03:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2A0B64FB1 for ; Wed, 17 Mar 2021 03:41:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229907AbhCQDkh (ORCPT ); Tue, 16 Mar 2021 23:40:37 -0400 Received: from mga11.intel.com ([192.55.52.93]:48803 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229727AbhCQDkS (ORCPT ); Tue, 16 Mar 2021 23:40:18 -0400 IronPort-SDR: PZSOib/skiKUSwZivqr63tqirww46ztIiopLYWt6NogEtY3ECTTmU4DWRhXpgkCBD5yTRIfyJd h2BwqpOhDHPg== X-IronPort-AV: E=McAfee;i="6000,8403,9925"; a="186021842" X-IronPort-AV: E=Sophos;i="5.81,254,1610438400"; d="scan'208";a="186021842" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Mar 2021 20:40:18 -0700 IronPort-SDR: FUGKoGaMedIKFszJHjI6qOR6Gp0cigBVXQvCIhQf3vMtwv/jmZWuIRvWG4fzg34tTfJMhwpIm4 lk17drMTYXDg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,254,1610438400"; d="scan'208";a="602075782" Received: from shbuild999.sh.intel.com ([10.239.147.94]) by fmsmga006.fm.intel.com with ESMTP; 16 Mar 2021 20:40:14 -0700 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 Kleen , Dan Williams , Feng Tang Subject: [PATCH v4 01/13] mm/mempolicy: Add comment for missing LOCAL Date: Wed, 17 Mar 2021 11:39:58 +0800 Message-Id: <1615952410-36895-2-git-send-email-feng.tang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1615952410-36895-1-git-send-email-feng.tang@intel.com> References: <1615952410-36895-1-git-send-email-feng.tang@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- mm/mempolicy.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index ab51132..4193566 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, -- 2.7.4