From patchwork Wed Oct 7 16:17:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Hansen X-Patchwork-Id: 11820975 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 80FFF1580 for ; Wed, 7 Oct 2020 16:18:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3A9BD217BA for ; Wed, 7 Oct 2020 16:18:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A9BD217BA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BFC2F6B0071; Wed, 7 Oct 2020 12:18:00 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id BD3976B0072; Wed, 7 Oct 2020 12:18:00 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A9F856B0073; Wed, 7 Oct 2020 12:18:00 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0075.hostedemail.com [216.40.44.75]) by kanga.kvack.org (Postfix) with ESMTP id 750E46B0071 for ; Wed, 7 Oct 2020 12:18:00 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 0AD86181AE86F for ; Wed, 7 Oct 2020 16:18:00 +0000 (UTC) X-FDA: 77345635920.04.store31_110f00e271d0 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id D54B8800004D for ; Wed, 7 Oct 2020 16:17:59 +0000 (UTC) X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,dave.hansen@linux.intel.com,,RULES_HIT:30004:30005:30054:30064,0,RBL:134.134.136.31:@linux.intel.com:.lbl8.mailshell.net-62.18.0.100 64.95.201.95;04yres3himbzmgpds8iob9zhc8gcooptrnq5wnhgagzbec3wjzjttia3zo6cq81.aajaz17bikepj7one7yk8acdk7okktbx5u14h5tg3cyidiw6fhjinn8g68ut9t5.1-lbl8.mailshell.net-223.238.255.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:25,LUA_SUMMARY:none X-HE-Tag: store31_110f00e271d0 X-Filterd-Recvd-Size: 5909 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Wed, 7 Oct 2020 16:17:58 +0000 (UTC) IronPort-SDR: aLcX8m6PyWpR9am6YUztU4nf+V4nDtZ4gI9czJDjqOkufMrg+jJbIfQBNfYBa2qt1NuAtngdeb QE25RhAJspvA== X-IronPort-AV: E=McAfee;i="6000,8403,9767"; a="226592680" X-IronPort-AV: E=Sophos;i="5.77,347,1596524400"; d="scan'208";a="226592680" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Oct 2020 09:17:57 -0700 IronPort-SDR: LZw/E6HmWncdT9wAseE8RuL19wYmYRoj0c/GHSXxCYNkh/Dv2rE5g2cD989oLIT8YookNH91wC 3eijvHzMCfxA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,347,1596524400"; d="scan'208";a="328125603" Received: from viggo.jf.intel.com (HELO localhost.localdomain) ([10.54.77.144]) by orsmga002.jf.intel.com with ESMTP; 07 Oct 2020 09:17:57 -0700 Subject: [RFC][PATCH 8/9] mm/vmscan: never demote for memcg reclaim To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org,Dave Hansen ,yang.shi@linux.alibaba.com,rientjes@google.com,ying.huang@intel.com,dan.j.williams@intel.com,david@redhat.com From: Dave Hansen Date: Wed, 07 Oct 2020 09:17:50 -0700 References: <20201007161736.ACC6E387@viggo.jf.intel.com> In-Reply-To: <20201007161736.ACC6E387@viggo.jf.intel.com> Message-Id: <20201007161750.74CE9FA2@viggo.jf.intel.com> 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 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. Signed-off-by: Dave Hansen Suggested-by: Yang Shi Cc: David Rientjes Cc: Huang Ying Cc: Dan Williams Cc: David Hildenbrand --- b/mm/vmscan.c | 33 +++++++++++++++++++++++++-------- 1 file changed, 25 insertions(+), 8 deletions(-) diff -puN mm/vmscan.c~never-demote-for-memcg-reclaim mm/vmscan.c --- a/mm/vmscan.c~never-demote-for-memcg-reclaim 2020-10-07 09:15:34.546642433 -0700 +++ b/mm/vmscan.c 2020-10-07 09:15:34.554642433 -0700 @@ -291,8 +291,11 @@ static bool writeback_throttling_sane(st #endif static inline bool can_reclaim_anon_pages(struct mem_cgroup *memcg, - int node_id) + int node_id, + struct scan_control *sc) { + bool in_cgroup_reclaim = false; + /* Always age anon pages when we have swap */ if (memcg == NULL) { if (get_nr_swap_pages() > 0) @@ -302,8 +305,18 @@ static inline bool can_reclaim_anon_page return true; } - /* Also age anon pages if we can auto-migrate them */ - if (next_demotion_node(node_id) >= 0) + /* Can only be in memcg reclaim in paths with valid 'sc': */ + if (sc && cgroup_reclaim(sc)) + in_cgroup_reclaim = true; + + /* + * Also age anon pages if we can auto-migrate them. + * + * Migrating a page does not reduce comsumption of a + * memcg so should not be performed when in memcg + * reclaim. + */ + if (!in_cgroup_reclaim && (next_demotion_node(node_id) >= 0)) return true; /* No way to reclaim anon pages */ @@ -321,7 +334,7 @@ unsigned long zone_reclaimable_pages(str nr = zone_page_state_snapshot(zone, NR_ZONE_INACTIVE_FILE) + zone_page_state_snapshot(zone, NR_ZONE_ACTIVE_FILE); - if (can_reclaim_anon_pages(NULL, zone_to_nid(zone))) + 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); @@ -1064,6 +1077,10 @@ bool migrate_demote_page_ok(struct page VM_BUG_ON_PAGE(PageHuge(page), page); VM_BUG_ON_PAGE(PageLRU(page), page); + /* It is pointless to do demotion in memcg reclaim */ + if (cgroup_reclaim(sc)) + return false; + if (next_nid == NUMA_NO_NODE) return false; if (PageTransHuge(page) && !thp_migration_supported()) @@ -2368,7 +2385,7 @@ static void get_scan_count(struct lruvec enum lru_list lru; /* If we have no swap space, do not bother scanning anon pages. */ - if (!sc->may_swap || !can_reclaim_anon_pages(memcg, pgdat->node_id)) { + if (!sc->may_swap || !can_reclaim_anon_pages(memcg, pgdat->node_id, sc)) { scan_balance = SCAN_FILE; goto out; } @@ -2653,7 +2670,7 @@ static void shrink_lruvec(struct lruvec * rebalance the anon lru active/inactive ratio. */ if (can_reclaim_anon_pages(lruvec_memcg(lruvec), - lruvec_pgdat(lruvec)->node_id) && + lruvec_pgdat(lruvec)->node_id, sc) && inactive_is_low(lruvec, LRU_INACTIVE_ANON)) shrink_active_list(SWAP_CLUSTER_MAX, lruvec, sc, LRU_ACTIVE_ANON); @@ -2724,7 +2741,7 @@ static inline bool should_continue_recla */ pages_for_compaction = compact_gap(sc->order); inactive_lru_pages = node_page_state(pgdat, NR_INACTIVE_FILE); - if (can_reclaim_anon_pages(NULL, pgdat->node_id)) + 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; @@ -3483,7 +3500,7 @@ static void age_active_anon(struct pglis struct mem_cgroup *memcg; struct lruvec *lruvec; - if (!can_reclaim_anon_pages(NULL, pgdat->node_id)) + if (!can_reclaim_anon_pages(NULL, pgdat->node_id, sc)) return; lruvec = mem_cgroup_lruvec(NULL, pgdat);