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=-9.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 8C392C04AB5 for ; Mon, 3 Jun 2019 22:10:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 484A5267B1 for ; Mon, 3 Jun 2019 22:10:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="yTHNUkzu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726721AbfFCWKv (ORCPT ); Mon, 3 Jun 2019 18:10:51 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:46122 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726102AbfFCWKv (ORCPT ); Mon, 3 Jun 2019 18:10:51 -0400 Received: by mail-pg1-f193.google.com with SMTP id v9so9038859pgr.13 for ; Mon, 03 Jun 2019 15:10:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=B6ockcEeDUtUJIvlx/DoCdCq85by+mHeIaqq/AmMtrQ=; b=yTHNUkzufxtfKAvZ8UcncxQaDV9qHqMwPaRk5AmPUtvARbAXYSqoPt3ofMv01d0IVK iq5U7nvDJ8vBmko1GaK2TR709/MyNG3qm2uSTW7dRg9eE71uW5vLMYGsmYte6+wfLRaE 5GKSSrFSsRhMFmNR16jq/rSVOoTVNyroChHLeKRWVj/c2bh0mvOgipIaBpWZcXeGN/D9 SvQM0GjhTA0oTOIG+m//ObL5L/IiQ6efS1GDg/J2rtN05JnTIU1VTH/rZWVL9SG0APMg /Yqy/0xBtIr31FfzTp67H6lg0r6x+o2rQFjdwXB4VjuV6R0OSBzszTpbsOt3VRhQlWSx f5kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=B6ockcEeDUtUJIvlx/DoCdCq85by+mHeIaqq/AmMtrQ=; b=VB2KmpRjLVlRU6ynoZE6/1t5IyruIL3AslXFHCWKZtZX3Bt6lRCinHXeKPReTuXUsy wUYySpqqoG9KczkMFMb8F2eJHCj+YSNekrhJF2FdlLv+PS7UmLuhxMQR45X4GlrvxDa4 VudwEV92rFZ59ypyQL+tioPWk3tlYdMku/VGBXobjKItLm1WFkJ9PgL6ApqAABGhpqkv u7f7/3BoWbhPyc16d0Kg5tSIWrMF4+v9XNF1KWCrN0N+WqOD6EsWrkXxiHgRYd7cq2N5 MpxrhfnJgRR6aXfO8AYFMqZMwVXRQTPr2H3goQcvC6g9QyiQcoDh0awtBgTAeKHGab5b q25g== X-Gm-Message-State: APjAAAVZT6cOSZ8Do0jOQwoM6cJphxS3oyQVlRgD/Mggm42wly7PGptV Z9IosCq9+gg/zda3XZGoRbGN6g== X-Google-Smtp-Source: APXvYqzuuFNtUjyKK1QDwjQku2LKUXQVeGjjjtfFcm0GcLid0BXMv6q6FaLzEqUddR/mQYmveXzu6A== X-Received: by 2002:a62:3741:: with SMTP id e62mr34248051pfa.213.1559596120271; Mon, 03 Jun 2019 14:08:40 -0700 (PDT) Received: from localhost ([2620:10d:c091:500::1:9fa4]) by smtp.gmail.com with ESMTPSA id l20sm15695900pff.102.2019.06.03.14.08.39 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 03 Jun 2019 14:08:39 -0700 (PDT) From: Johannes Weiner To: Andrew Morton Cc: Andrey Ryabinin , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 08/11] mm: vmscan: harmonize writeback congestion tracking for nodes & memcgs Date: Mon, 3 Jun 2019 17:07:43 -0400 Message-Id: <20190603210746.15800-9-hannes@cmpxchg.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190603210746.15800-1-hannes@cmpxchg.org> References: <20190603210746.15800-1-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The current writeback congestion tracking has separate flags for kswapd reclaim (node level) and cgroup limit reclaim (memcg-node level). This is unnecessarily complicated: the lruvec is an existing abstraction layer for that node-memcg intersection. Introduce lruvec->flags and LRUVEC_CONGESTED. Then track that at the reclaim root level, which is either the NUMA node for global reclaim, or the cgroup-node intersection for cgroup reclaim. Signed-off-by: Johannes Weiner --- include/linux/memcontrol.h | 6 +-- include/linux/mmzone.h | 11 ++++-- mm/vmscan.c | 80 ++++++++++++-------------------------- 3 files changed, 36 insertions(+), 61 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index fc32cfaebf32..d33e09c51acc 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -144,9 +144,6 @@ struct mem_cgroup_per_node { unsigned long usage_in_excess;/* Set to the value by which */ /* the soft limit is exceeded*/ bool on_tree; - bool congested; /* memcg has many dirty pages */ - /* backed by a congested BDI */ - struct mem_cgroup *memcg; /* Back pointer, we cannot */ /* use container_of */ }; @@ -401,6 +398,9 @@ static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg, goto out; } + if (!memcg) + memcg = root_mem_cgroup; + mz = mem_cgroup_nodeinfo(memcg, pgdat->node_id); lruvec = &mz->lruvec; out: diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 95d63a395f40..b3ab64cf5619 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -293,6 +293,12 @@ struct zone_reclaim_stat { unsigned long recent_scanned[2]; }; +enum lruvec_flags { + LRUVEC_CONGESTED, /* lruvec has many dirty pages + * backed by a congested BDI + */ +}; + struct lruvec { struct list_head lists[NR_LRU_LISTS]; struct zone_reclaim_stat reclaim_stat; @@ -300,6 +306,8 @@ struct lruvec { atomic_long_t inactive_age; /* Refaults at the time of last reclaim cycle */ unsigned long refaults; + /* Various lruvec state flags (enum lruvec_flags) */ + unsigned long flags; #ifdef CONFIG_MEMCG struct pglist_data *pgdat; #endif @@ -562,9 +570,6 @@ struct zone { } ____cacheline_internodealigned_in_smp; enum pgdat_flags { - PGDAT_CONGESTED, /* pgdat has many dirty pages backed by - * a congested BDI - */ PGDAT_DIRTY, /* reclaim scanning has recently found * many dirty file pages at the tail * of the LRU. diff --git a/mm/vmscan.c b/mm/vmscan.c index ee79b39d0538..eb535c572733 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -267,29 +267,6 @@ static bool writeback_working(struct scan_control *sc) #endif return false; } - -static void set_memcg_congestion(pg_data_t *pgdat, - struct mem_cgroup *memcg, - bool congested) -{ - struct mem_cgroup_per_node *mn; - - if (!memcg) - return; - - mn = mem_cgroup_nodeinfo(memcg, pgdat->node_id); - WRITE_ONCE(mn->congested, congested); -} - -static bool memcg_congested(pg_data_t *pgdat, - struct mem_cgroup *memcg) -{ - struct mem_cgroup_per_node *mn; - - mn = mem_cgroup_nodeinfo(memcg, pgdat->node_id); - return READ_ONCE(mn->congested); - -} #else static bool cgroup_reclaim(struct scan_control *sc) { @@ -300,18 +277,6 @@ static bool writeback_working(struct scan_control *sc) { return true; } - -static inline void set_memcg_congestion(struct pglist_data *pgdat, - struct mem_cgroup *memcg, bool congested) -{ -} - -static inline bool memcg_congested(struct pglist_data *pgdat, - struct mem_cgroup *memcg) -{ - return false; - -} #endif /* @@ -2659,12 +2624,6 @@ static inline bool should_continue_reclaim(struct pglist_data *pgdat, return true; } -static bool pgdat_memcg_congested(pg_data_t *pgdat, struct mem_cgroup *memcg) -{ - return test_bit(PGDAT_CONGESTED, &pgdat->flags) || - (memcg && memcg_congested(pgdat, memcg)); -} - static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc) { struct mem_cgroup *root = sc->target_mem_cgroup; @@ -2748,8 +2707,11 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) struct reclaim_state *reclaim_state = current->reclaim_state; struct mem_cgroup *root = sc->target_mem_cgroup; unsigned long nr_reclaimed, nr_scanned; + struct lruvec *target_lruvec; bool reclaimable = false; + target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat); + again: memset(&sc->nr, 0, sizeof(sc->nr)); @@ -2792,14 +2754,6 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) if (sc->nr.writeback && sc->nr.writeback == sc->nr.taken) set_bit(PGDAT_WRITEBACK, &pgdat->flags); - /* - * Tag a node as congested if all the dirty pages - * scanned were backed by a congested BDI and - * wait_iff_congested will stall. - */ - if (sc->nr.dirty && sc->nr.dirty == sc->nr.congested) - set_bit(PGDAT_CONGESTED, &pgdat->flags); - /* Allow kswapd to start writing pages during reclaim.*/ if (sc->nr.unqueued_dirty == sc->nr.file_taken) set_bit(PGDAT_DIRTY, &pgdat->flags); @@ -2815,12 +2769,17 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) } /* + * Tag a node/memcg as congested if all the dirty pages + * scanned were backed by a congested BDI and + * wait_iff_congested will stall. + * * Legacy memcg will stall in page writeback so avoid forcibly * stalling in wait_iff_congested(). */ - if (cgroup_reclaim(sc) && writeback_working(sc) && + if ((current_is_kswapd() || + (cgroup_reclaim(sc) && writeback_working(sc))) && sc->nr.dirty && sc->nr.dirty == sc->nr.congested) - set_memcg_congestion(pgdat, root, true); + set_bit(LRUVEC_CONGESTED, &target_lruvec->flags); /* * Stall direct reclaim for IO completions if underlying BDIs @@ -2828,8 +2787,9 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) * starts encountering unqueued dirty pages or cycling through * the LRU too quickly. */ - if (!sc->hibernation_mode && !current_is_kswapd() && - current_may_throttle() && pgdat_memcg_congested(pgdat, root)) + if (!current_is_kswapd() && current_may_throttle() && + !sc->hibernation_mode && + test_bit(LRUVEC_CONGESTED, &target_lruvec->flags)) wait_iff_congested(BLK_RW_ASYNC, HZ/10); if (should_continue_reclaim(pgdat, sc->nr_reclaimed - nr_reclaimed, @@ -3043,8 +3003,16 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, if (zone->zone_pgdat == last_pgdat) continue; last_pgdat = zone->zone_pgdat; + snapshot_refaults(sc->target_mem_cgroup, zone->zone_pgdat); - set_memcg_congestion(last_pgdat, sc->target_mem_cgroup, false); + + if (cgroup_reclaim(sc)) { + struct lruvec *lruvec; + + lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, + zone->zone_pgdat); + clear_bit(LRUVEC_CONGESTED, &lruvec->flags); + } } delayacct_freepages_end(); @@ -3419,7 +3387,9 @@ static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx) /* Clear pgdat state for congested, dirty or under writeback. */ static void clear_pgdat_congested(pg_data_t *pgdat) { - clear_bit(PGDAT_CONGESTED, &pgdat->flags); + struct lruvec *lruvec = mem_cgroup_lruvec(NULL, pgdat); + + clear_bit(LRUVEC_CONGESTED, &lruvec->flags); clear_bit(PGDAT_DIRTY, &pgdat->flags); clear_bit(PGDAT_WRITEBACK, &pgdat->flags); } -- 2.21.0