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=unavailable 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 D78F9C2B9F4 for ; Fri, 25 Jun 2021 07:33:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5EA76141E for ; Fri, 25 Jun 2021 07:33:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230116AbhFYHgJ (ORCPT ); Fri, 25 Jun 2021 03:36:09 -0400 Received: from mga06.intel.com ([134.134.136.31]:11597 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230031AbhFYHgG (ORCPT ); Fri, 25 Jun 2021 03:36:06 -0400 IronPort-SDR: DmDdt9LJQ0XfpLKPDFRAhKss8zpqgXEFXqlwwlCNFe7qwAmEeo3TpxSHScIToNiokqOT6bfTcU hemEfmKMfEuw== X-IronPort-AV: E=McAfee;i="6200,9189,10025"; a="268757361" X-IronPort-AV: E=Sophos;i="5.83,298,1616482800"; d="scan'208";a="268757361" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Jun 2021 00:33:36 -0700 IronPort-SDR: Klbbr54x4EkA6AacRtKb5x5p7zTnsVw+sXoQTribn1+RoFRU6Nittd/rKO0ABnuMrc2LPAV8GU IJAhHIl9NMBQ== X-IronPort-AV: E=Sophos;i="5.83,298,1616482800"; d="scan'208";a="488085893" Received: from msun2-mobl1.ccr.corp.intel.com (HELO yhuang6-mobl1.ccr.corp.intel.com) ([10.254.215.50]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Jun 2021 00:33:23 -0700 From: Huang Ying To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Keith Busch , Dave Hansen , "Huang, Ying" , Yang Shi , Michal Hocko , Zi Yan , Wei Xu , David Rientjes , Dan Williams , David Hildenbrand Subject: [PATCH -V9 7/9] mm/vmscan: Consider anonymous pages without swap Date: Fri, 25 Jun 2021 15:32:02 +0800 Message-Id: <20210625073204.1005986-8-ying.huang@intel.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210625073204.1005986-1-ying.huang@intel.com> References: <20210625073204.1005986-1-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: Keith Busch Reclaim anonymous pages if a migration path is available now that demotion provides a non-swap recourse for reclaiming anon pages. Note that this check is subtly different from the anon_should_be_aged() checks. This mechanism checks whether a specific page in a specific context *can* actually be reclaimed, given current swap space and cgroup limits anon_should_be_aged() is a much simpler and more preliminary check which just says whether there is a possibility of future reclaim. Cc: Keith Busch Signed-off-by: Dave Hansen Signed-off-by: "Huang, Ying" Reviewed-by: Yang Shi Cc: Michal Hocko Cc: Zi Yan Cc: Wei Xu Cc: David Rientjes Cc: Dan Williams Cc: David Hildenbrand -- Changes since 20210618: * Consider whether demotion is disabled Changes from Dave 202010: * remove 'total_swap_pages' modification Changes from Dave 202006: * rename reclaim_anon_pages()->can_reclaim_anon_pages() Note: Keith's Intel SoB is commented out because he is no longer at Intel and his @intel.com mail will bounce. --- mm/vmscan.c | 37 ++++++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 55f6192b2a51..fce43c7970d7 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -519,6 +519,36 @@ static long add_nr_deferred(long nr, struct shrinker *shrinker, return atomic_long_add_return(nr, &shrinker->nr_deferred[nid]); } +static inline bool can_reclaim_anon_pages(struct mem_cgroup *memcg, + int node_id, + struct scan_control *sc) +{ + if (memcg == NULL) { + /* + * For non-memcg reclaim, is there + * space in any swap device? + */ + if (get_nr_swap_pages() > 0) + return true; + } else { + /* Is the memcg below its swap limit? */ + if (mem_cgroup_get_nr_swap_pages(memcg) > 0) + return true; + } + + /* + * The page can not be swapped. + * + * Can it be reclaimed from this node via demotion? + */ + if ((!sc || !sc->no_demotion) && + next_demotion_node(node_id) != NUMA_NO_NODE) + return true; + + /* No way to reclaim anon pages */ + return false; +} + /* * This misses isolated pages which are not accounted for to save counters. * As the data only determines if reclaim or compaction continues, it is @@ -530,7 +560,7 @@ unsigned long zone_reclaimable_pages(struct zone *zone) nr = zone_page_state_snapshot(zone, NR_ZONE_INACTIVE_FILE) + zone_page_state_snapshot(zone, NR_ZONE_ACTIVE_FILE); - if (get_nr_swap_pages() > 0) + if (can_reclaim_anon_pages(NULL, zone_to_nid(zone), NULL)) nr += zone_page_state_snapshot(zone, NR_ZONE_INACTIVE_ANON) + zone_page_state_snapshot(zone, NR_ZONE_ACTIVE_ANON); @@ -2531,6 +2561,7 @@ enum scan_balance { static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, unsigned long *nr) { + struct pglist_data *pgdat = lruvec_pgdat(lruvec); struct mem_cgroup *memcg = lruvec_memcg(lruvec); unsigned long anon_cost, file_cost, total_cost; int swappiness = mem_cgroup_swappiness(memcg); @@ -2541,7 +2572,7 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, enum lru_list lru; /* If we have no swap space, do not bother scanning anon pages. */ - if (!sc->may_swap || mem_cgroup_get_nr_swap_pages(memcg) <= 0) { + if (!sc->may_swap || !can_reclaim_anon_pages(memcg, pgdat->node_id, sc)) { scan_balance = SCAN_FILE; goto out; } @@ -2916,7 +2947,7 @@ static inline bool should_continue_reclaim(struct pglist_data *pgdat, */ pages_for_compaction = compact_gap(sc->order); inactive_lru_pages = node_page_state(pgdat, NR_INACTIVE_FILE); - if (get_nr_swap_pages() > 0) + if (can_reclaim_anon_pages(NULL, pgdat->node_id, sc)) inactive_lru_pages += node_page_state(pgdat, NR_INACTIVE_ANON); return inactive_lru_pages > pages_for_compaction; -- 2.30.2