From patchwork Wed Jul 21 06:39:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Ying" X-Patchwork-Id: 12390113 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 17984C636C9 for ; Wed, 21 Jul 2021 06:41:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B7B9361029 for ; Wed, 21 Jul 2021 06:41:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B7B9361029 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 E51AA6B0072; Wed, 21 Jul 2021 02:41:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DB5516B0073; Wed, 21 Jul 2021 02:41:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C05626B0074; Wed, 21 Jul 2021 02:41:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0108.hostedemail.com [216.40.44.108]) by kanga.kvack.org (Postfix) with ESMTP id 9ED836B0072 for ; Wed, 21 Jul 2021 02:41:17 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 238928248047 for ; Wed, 21 Jul 2021 06:41:16 +0000 (UTC) X-FDA: 78385648152.15.B35CCB9 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf17.hostedemail.com (Postfix) with ESMTP id 83BFDF009AC3 for ; Wed, 21 Jul 2021 06:41:15 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10051"; a="272496390" X-IronPort-AV: E=Sophos;i="5.84,257,1620716400"; d="scan'208";a="272496390" 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 23:39:53 -0700 X-IronPort-AV: E=Sophos;i="5.84,257,1620716400"; d="scan'208";a="511390027" 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 23:39:50 -0700 From: Huang Ying To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dave Hansen , "Huang, Ying" , Yang Shi , Greg Thelen , Michal Hocko , Wei Xu , Oscar Salvador , Zi Yan , David Rientjes , Dan Williams , David Hildenbrand , Keith Busch , Yang Shi Subject: [PATCH -V11 6/9] mm/vmscan: add helper for querying ability to age anonymous pages Date: Wed, 21 Jul 2021 14:39:23 +0800 Message-Id: <20210721063926.3024591-6-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 Authentication-Results: imf17.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=intel.com (policy=none); spf=none (imf17.hostedemail.com: domain of ying.huang@intel.com has no SPF policy when checking 134.134.136.31) smtp.mailfrom=ying.huang@intel.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 83BFDF009AC3 X-Stat-Signature: xdtkcyc5aet1spbanoem83ha6wgfbuj4 X-HE-Tag: 1626849675-252809 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 Anonymous pages are kept on their own LRU(s). These lists could theoretically always be scanned and maintained. But, without swap, there is currently nothing the kernel can *do* with the results of a scanned, sorted LRU for anonymous pages. A check for '!total_swap_pages' currently serves as a valid check as to whether anonymous LRUs should be maintained. However, another method will be added shortly: page demotion. Abstract out the 'total_swap_pages' checks into a helper, give it a logically significant name, and check for the possibility of page demotion. Link: https://lkml.kernel.org/r/20210715055145.195411-7-ying.huang@intel.com Signed-off-by: Dave Hansen Signed-off-by: "Huang, Ying" Reviewed-by: Yang Shi Reviewed-by: Greg Thelen Cc: Michal Hocko Cc: Wei Xu Cc: Oscar Salvador Cc: Zi Yan Cc: David Rientjes Cc: Dan Williams Cc: David Hildenbrand Cc: Keith Busch Cc: Yang Shi Signed-off-by: Andrew Morton --- mm/vmscan.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 90fa026cfa29..d79bf91700de 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2729,6 +2729,21 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, } } +/* + * Anonymous LRU management is a waste if there is + * ultimately no way to reclaim the memory. + */ +static bool can_age_anon_pages(struct pglist_data *pgdat, + struct scan_control *sc) +{ + /* Aging the anon LRU is valuable if swap is present: */ + if (total_swap_pages > 0) + return true; + + /* Also valuable if anon pages can be demoted: */ + return can_demote(pgdat->node_id, sc); +} + static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc) { unsigned long nr[NR_LRU_LISTS]; @@ -2838,7 +2853,8 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc) * Even if we did not try to evict anon pages at all, we want to * rebalance the anon lru active/inactive ratio. */ - if (total_swap_pages && inactive_is_low(lruvec, LRU_INACTIVE_ANON)) + if (can_age_anon_pages(lruvec_pgdat(lruvec), sc) && + inactive_is_low(lruvec, LRU_INACTIVE_ANON)) shrink_active_list(SWAP_CLUSTER_MAX, lruvec, sc, LRU_ACTIVE_ANON); } @@ -3669,7 +3685,7 @@ static void age_active_anon(struct pglist_data *pgdat, struct mem_cgroup *memcg; struct lruvec *lruvec; - if (!total_swap_pages) + if (!can_age_anon_pages(pgdat, sc)) return; lruvec = mem_cgroup_lruvec(NULL, pgdat);