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 9BDD9C636C9 for ; Wed, 21 Jul 2021 06:44:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E6A061175 for ; Wed, 21 Jul 2021 06:44:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234709AbhGUGDW (ORCPT ); Wed, 21 Jul 2021 02:03:22 -0400 Received: from mga06.intel.com ([134.134.136.31]:44388 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234275AbhGUF70 (ORCPT ); Wed, 21 Jul 2021 01:59:26 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10051"; a="272496401" X-IronPort-AV: E=Sophos;i="5.84,257,1620716400"; d="scan'208";a="272496401" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2021 23:40:00 -0700 X-IronPort-AV: E=Sophos;i="5.84,257,1620716400"; d="scan'208";a="511390055" Received: from yhuang6-desk2.sh.intel.com ([10.239.159.119]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jul 2021 23:39:57 -0700 From: Huang Ying To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dave Hansen , "Huang, Ying" , Yang Shi , Yang Shi , Michal Hocko , Wei Xu , Oscar Salvador , Zi Yan , David Rientjes , Dan Williams , David Hildenbrand , Greg Thelen , Keith Busch Subject: [PATCH -V11 8/9] mm/vmscan: never demote for memcg reclaim Date: Wed, 21 Jul 2021 14:39:25 +0800 Message-Id: <20210721063926.3024591-8-ying.huang@intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210721063926.3024591-1-ying.huang@intel.com> References: <20210721063926.3024591-1-ying.huang@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Hansen Global reclaim aims to reduce the amount of memory used on a given node or set of nodes. Migrating pages to another node serves this purpose. memcg reclaim is different. Its goal is to reduce the total memory consumption of the entire memcg, across all nodes. Migration does not assist memcg reclaim because it just moves page contents between nodes rather than actually reducing memory consumption. Link: https://lkml.kernel.org/r/20210715055145.195411-9-ying.huang@intel.com Signed-off-by: Dave Hansen Signed-off-by: "Huang, Ying" Suggested-by: Yang Shi Reviewed-by: Yang Shi Cc: Michal Hocko Cc: Wei Xu Cc: Oscar Salvador Cc: Zi Yan Cc: David Rientjes Cc: Dan Williams Cc: David Hildenbrand Cc: Greg Thelen Cc: Keith Busch Signed-off-by: Andrew Morton --- mm/vmscan.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 67a320c6571d..60179903ed9e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -521,8 +521,13 @@ static long add_nr_deferred(long nr, struct shrinker *shrinker, static bool can_demote(int nid, struct scan_control *sc) { - if (sc && sc->no_demotion) - return false; + if (sc) { + if (sc->no_demotion) + return false; + /* It is pointless to do demotion in memcg reclaim */ + if (cgroup_reclaim(sc)) + return false; + } if (next_demotion_node(nid) == NUMA_NO_NODE) return false; -- 2.30.2