From patchwork Mon Sep 20 08:54:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mel Gorman X-Patchwork-Id: 12504857 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 24F3FC433EF for ; Mon, 20 Sep 2021 08:55:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A99A1601FF for ; Mon, 20 Sep 2021 08:55:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A99A1601FF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 5261C940009; Mon, 20 Sep 2021 04:55:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 48749900002; Mon, 20 Sep 2021 04:55:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 34F3F940009; Mon, 20 Sep 2021 04:55:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0114.hostedemail.com [216.40.44.114]) by kanga.kvack.org (Postfix) with ESMTP id 23C6B900002 for ; Mon, 20 Sep 2021 04:55:22 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id DAE6E180AD82F for ; Mon, 20 Sep 2021 08:55:21 +0000 (UTC) X-FDA: 78607342842.18.C16A281 Received: from outbound-smtp38.blacknight.com (outbound-smtp38.blacknight.com [46.22.139.221]) by imf30.hostedemail.com (Postfix) with ESMTP id 5D414E00199C for ; Mon, 20 Sep 2021 08:55:21 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp38.blacknight.com (Postfix) with ESMTPS id 28AC52984 for ; Mon, 20 Sep 2021 09:55:20 +0100 (IST) Received: (qmail 28151 invoked from network); 20 Sep 2021 08:55:19 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.17.29]) by 81.17.254.9 with ESMTPA; 20 Sep 2021 08:55:19 -0000 From: Mel Gorman To: Linux-MM Cc: NeilBrown , Theodore Ts'o , Andreas Dilger , "Darrick J . Wong" , Matthew Wilcox , Michal Hocko , Dave Chinner , Rik van Riel , Vlastimil Babka , Johannes Weiner , Jonathan Corbet , Linux-fsdevel , LKML , Mel Gorman Subject: [PATCH 3/5] mm/vmscan: Throttle reclaim when no progress is being made Date: Mon, 20 Sep 2021 09:54:34 +0100 Message-Id: <20210920085436.20939-4-mgorman@techsingularity.net> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210920085436.20939-1-mgorman@techsingularity.net> References: <20210920085436.20939-1-mgorman@techsingularity.net> MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 5D414E00199C X-Stat-Signature: f91eduq6i6o6xrnwohjt5i9zirhx3373 Authentication-Results: imf30.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf30.hostedemail.com: domain of mgorman@techsingularity.net designates 46.22.139.221 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net X-HE-Tag: 1632128121-814121 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: Memcg reclaim throttles on congestion if no reclaim progress is made. This makes little sense, it might be due to writeback or a host of other factors. For !memcg reclaim, it's messy. Direct reclaim primarily is throttled in the page allocator if it is failing to make progress. Kswapd throttles if too many pages are under writeback and marked for immediate reclaim. This patch explicitly throttles if reclaim is failing to make progress. Signed-off-by: Mel Gorman Signed-off-by: Mel Gorman --- include/linux/mmzone.h | 1 + include/trace/events/vmscan.h | 4 +++- mm/memcontrol.c | 10 +-------- mm/vmscan.c | 38 +++++++++++++++++++++++++++++++++++ 4 files changed, 43 insertions(+), 10 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index ca65d6a64bdd..7c08cc91d526 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -276,6 +276,7 @@ enum lru_list { enum vmscan_throttle_state { VMSCAN_THROTTLE_WRITEBACK, VMSCAN_THROTTLE_ISOLATED, + VMSCAN_THROTTLE_NOPROGRESS, NR_VMSCAN_THROTTLE, }; diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h index d4905bd9e9c4..f25a6149d3ba 100644 --- a/include/trace/events/vmscan.h +++ b/include/trace/events/vmscan.h @@ -29,11 +29,13 @@ #define _VMSCAN_THROTTLE_WRITEBACK (1 << VMSCAN_THROTTLE_WRITEBACK) #define _VMSCAN_THROTTLE_ISOLATED (1 << VMSCAN_THROTTLE_ISOLATED) +#define _VMSCAN_THROTTLE_NOPROGRESS (1 << VMSCAN_THROTTLE_NOPROGRESS) #define show_throttle_flags(flags) \ (flags) ? __print_flags(flags, "|", \ {_VMSCAN_THROTTLE_WRITEBACK, "VMSCAN_THROTTLE_WRITEBACK"}, \ - {_VMSCAN_THROTTLE_ISOLATED, "VMSCAN_THROTTLE_ISOLATED"} \ + {_VMSCAN_THROTTLE_ISOLATED, "VMSCAN_THROTTLE_ISOLATED"}, \ + {_VMSCAN_THROTTLE_NOPROGRESS, "VMSCAN_THROTTLE_NOPROGRESS"} \ ) : "VMSCAN_THROTTLE_NONE" diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b762215d73eb..8479919a633c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3470,19 +3470,11 @@ static int mem_cgroup_force_empty(struct mem_cgroup *memcg) /* try to free all pages in this cgroup */ while (nr_retries && page_counter_read(&memcg->memory)) { - int progress; - if (signal_pending(current)) return -EINTR; - progress = try_to_free_mem_cgroup_pages(memcg, 1, - GFP_KERNEL, true); - if (!progress) { + if (!try_to_free_mem_cgroup_pages(memcg, 1, GFP_KERNEL, true)) nr_retries--; - /* maybe some writeback is necessary */ - congestion_wait(BLK_RW_ASYNC, HZ/10); - } - } return 0; diff --git a/mm/vmscan.c b/mm/vmscan.c index eb81dcac15b2..18b9826953a0 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3307,6 +3307,33 @@ static inline bool compaction_ready(struct zone *zone, struct scan_control *sc) return zone_watermark_ok_safe(zone, 0, watermark, sc->reclaim_idx); } +static void consider_reclaim_throttle(pg_data_t *pgdat, struct scan_control *sc) +{ + /* If reclaim is making progress, wake any throttled tasks. */ + if (sc->nr_reclaimed) { + wait_queue_head_t *wqh; + + wqh = &pgdat->reclaim_wait[VMSCAN_THROTTLE_NOPROGRESS]; + if (waitqueue_active(wqh)) + wake_up_interruptible_all(wqh); + + return; + } + + /* + * Do not throttle kswapd on NOPROGRESS as it will throttle on + * VMSCAN_THROTTLE_WRITEBACK if there are too many pages under + * writeback and marked for immediate reclaim at the tail of + * the LRU. + */ + if (current_is_kswapd()) + return; + + /* Throttle if making no progress at high prioities. */ + if (sc->priority < DEF_PRIORITY - 2) + reclaim_throttle(pgdat, VMSCAN_THROTTLE_NOPROGRESS, HZ/10); +} + /* * This is the direct reclaim path, for page-allocating processes. We only * try to reclaim pages from zones which will satisfy the caller's allocation @@ -3391,6 +3418,7 @@ static void shrink_zones(struct zonelist *zonelist, struct scan_control *sc) continue; last_pgdat = zone->zone_pgdat; shrink_node(zone->zone_pgdat, sc); + consider_reclaim_throttle(zone->zone_pgdat, sc); } /* @@ -3765,6 +3793,16 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed); set_task_reclaim_state(current, NULL); + if (!nr_reclaimed) { + struct zoneref *z; + pg_data_t *pgdat; + + z = first_zones_zonelist(zonelist, sc.reclaim_idx, sc.nodemask); + pgdat = zonelist_zone(z)->zone_pgdat; + + reclaim_throttle(pgdat, VMSCAN_THROTTLE_NOPROGRESS, HZ/10); + } + return nr_reclaimed; } #endif