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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 341A9C43217 for ; Thu, 2 Sep 2021 21:59:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E2475603E9 for ; Thu, 2 Sep 2021 21:59:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org E2475603E9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 84DA96B0186; Thu, 2 Sep 2021 17:59:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7D64894000D; Thu, 2 Sep 2021 17:59:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 650A294000C; Thu, 2 Sep 2021 17:59:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0096.hostedemail.com [216.40.44.96]) by kanga.kvack.org (Postfix) with ESMTP id 4BCAE6B0186 for ; Thu, 2 Sep 2021 17:59:32 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 0DFFC2A4B5 for ; Thu, 2 Sep 2021 21:59:32 +0000 (UTC) X-FDA: 78544000584.27.7DC54FC Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf21.hostedemail.com (Postfix) with ESMTP id C467ED0272A3 for ; Thu, 2 Sep 2021 21:59:31 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 6860A60F12; Thu, 2 Sep 2021 21:59:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1630619970; bh=D16OA151Vtwjrpdv0CNg/AkIJWVfNXLlsPCbXM1050U=; h=Date:From:To:Subject:In-Reply-To:From; b=rVR7JvjVcaKe8zL+f1ADp4WM4HB7CodAXJuckvtilgC1zGXySMAyQdug03Dus9ubH Ft8tQM60okzv+2TTDgDSBfMvNY5/BU82KPvMKGhaKPJcWKGULpEQ8gIc9YFTCsWod/ 2tvY1mBRFmONlDswSTE0kfCGwfmJLyR4Fg7nCGJ0= Date: Thu, 02 Sep 2021 14:59:30 -0700 From: Andrew Morton To: akpm@linux-foundation.org, dan.j.williams@intel.com, dave.hansen@linux.intel.com, david@redhat.com, gthelen@google.com, kbusch@kernel.org, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, osalvador@suse.de, rientjes@google.com, shy828301@gmail.com, torvalds@linux-foundation.org, weixugc@google.com, yang.shi@linux.alibaba.com, ying.huang@intel.com, ziy@nvidia.com Subject: [patch 180/212] mm/vmscan: never demote for memcg reclaim Message-ID: <20210902215930.MtR2KoOu5%akpm@linux-foundation.org> In-Reply-To: <20210902144820.78957dff93d7bea620d55a89@linux-foundation.org> User-Agent: s-nail v14.8.16 Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=rVR7JvjV; spf=pass (imf21.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: C467ED0272A3 X-Stat-Signature: 76i8upgunkcxjxrwwj63up73r47dgg6b X-HE-Tag: 1630619971-389387 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: Dave Hansen Subject: mm/vmscan: never demote for memcg reclaim 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 Reviewed-by: Zi Yan Cc: Michal Hocko Cc: Wei Xu Cc: Oscar Salvador 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(-) --- a/mm/vmscan.c~mm-vmscan-never-demote-for-memcg-reclaim +++ a/mm/vmscan.c @@ -524,8 +524,13 @@ static long add_nr_deferred(long nr, str 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; _