From patchwork Tue Jan 4 20:22:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Zhao X-Patchwork-Id: 12703833 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34153C433FE for ; Tue, 4 Jan 2022 20:23:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3A2486B0075; Tue, 4 Jan 2022 15:23:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2DE0A6B0078; Tue, 4 Jan 2022 15:23:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 130646B007B; Tue, 4 Jan 2022 15:23:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0166.hostedemail.com [216.40.44.166]) by kanga.kvack.org (Postfix) with ESMTP id F05B66B0075 for ; Tue, 4 Jan 2022 15:23:26 -0500 (EST) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id ABB95824CA01 for ; Tue, 4 Jan 2022 20:23:26 +0000 (UTC) X-FDA: 78993729612.04.BDCFC53 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) by imf10.hostedemail.com (Postfix) with ESMTP id A7BA1C000A for ; Tue, 4 Jan 2022 20:23:13 +0000 (UTC) Received: by mail-yb1-f201.google.com with SMTP id a9-20020a251a09000000b0060b2c94d515so54148419yba.20 for ; Tue, 04 Jan 2022 12:23:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=6EZGTngPExZbz9sWlVRVd8w5b6kFwoRqMuezfZ9tNbk=; b=FVs55Yb6/Nspx39BsTcLZuOUTapsn5A5d3bna2dmPJ7Al+gZu/85lHVv0hO2w1aZ2I sJb9YGtJKX/2MuMSY5e3iX2wg9zvuFXlfXKQLGu1B1rRKLT5g2yPfyFzEhgVEdjbnPIB imLd4EeQrhqnJeCDTMDBmqMDsBXOauet3z4CAemjjgabmqmmC8398eJ0BQ03qH6nmG9w s6ltbPKaTMgTTFMeDQhhgHjAj41Dn9rSHlsI9cNgDPNr15yNB1qe4wnvqhTeK2hmcSIH BygxgfmOneoDASfAKoh7H55bRvtAfIexdu4PLs7kmaPRn/74sNdptoX24k62vk6Hvpz+ naOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=6EZGTngPExZbz9sWlVRVd8w5b6kFwoRqMuezfZ9tNbk=; b=txcd2FfOwyQilgHNxR5SNnKUx62AD3m1rvzu1EXpgK86Bys7U8gYvohJ5mc1goTCRB zkXYzhxY6Uxv7BSV9HgXJsPG29ikfeMglIkBHyu+HIarROvGicgbJpf64JlG6WJ4dhLa PoDvYYTZ72GdpKaU5UFg4pGiJxQzD/JyPyTIpshzl3JMRhfaE0RAYVd8nLarKxnS0fpr X3q00j5hYJt8IBLnhAZGNBP+wDKPQWMEIascT7O4sELS9aR/jCAR9lBz7V+4/jDTBE2Q yVZ6kAIUZZKFmfeWB4G4E+1Rbgfz48ejbAKWyYdkz9Q/qXEvryOxSst+5wRCOz2Kt/Ns OeaA== X-Gm-Message-State: AOAM533JBY3q6RGrjTEvQCS1brmEHI0F5IS/uIvv7/JBoxwHEEYL9ZE4 7ubo5rG7okxXMmMY5oGIaXcgiJvMkV8= X-Google-Smtp-Source: ABdhPJzbwhddtXqgKUia2YA9SP+Q+rZTdck2992kBQ7auwgVPcZUUo837l5/N8hQrKaoytrK2eKF2x0nC/0= X-Received: from yuzhao.bld.corp.google.com ([2620:15c:183:200:6c8c:5506:7ca2:9dfd]) (user=yuzhao job=sendgmr) by 2002:a25:4b85:: with SMTP id y127mr63132951yba.181.1641327805472; Tue, 04 Jan 2022 12:23:25 -0800 (PST) Date: Tue, 4 Jan 2022 13:22:22 -0700 In-Reply-To: <20220104202227.2903605-1-yuzhao@google.com> Message-Id: <20220104202227.2903605-4-yuzhao@google.com> Mime-Version: 1.0 References: <20220104202227.2903605-1-yuzhao@google.com> X-Mailer: git-send-email 2.34.1.448.ga2b2bfdf31-goog Subject: [PATCH v6 3/9] mm/vmscan.c: refactor shrink_node() From: Yu Zhao To: Andrew Morton , Linus Torvalds Cc: Andi Kleen , Catalin Marinas , Dave Hansen , Hillf Danton , Jens Axboe , Jesse Barnes , Johannes Weiner , Jonathan Corbet , Matthew Wilcox , Mel Gorman , Michael Larabel , Michal Hocko , Rik van Riel , Vlastimil Babka , Will Deacon , Ying Huang , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, page-reclaim@google.com, x86@kernel.org, Yu Zhao , Konstantin Kharlamov X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: A7BA1C000A X-Stat-Signature: w4o11az9afkzcyhhnanuyki9pg33misr Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=FVs55Yb6; spf=pass (imf10.hostedemail.com: domain of 3vazUYQYKCH40w1jcqiqqing.eqonkpwz-oomxcem.qti@flex--yuzhao.bounces.google.com designates 209.85.219.201 as permitted sender) smtp.mailfrom=3vazUYQYKCH40w1jcqiqqing.eqonkpwz-oomxcem.qti@flex--yuzhao.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com X-HE-Tag: 1641327793-548019 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: This patch refactors shrink_node() to improve readability for the upcoming changes to mm/vmscan.c. Signed-off-by: Yu Zhao Tested-by: Konstantin Kharlamov --- mm/vmscan.c | 198 +++++++++++++++++++++++++++------------------------- 1 file changed, 104 insertions(+), 94 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 700434db5735..b6c5fd885216 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2716,6 +2716,109 @@ enum scan_balance { SCAN_FILE, }; +static void prepare_scan_count(pg_data_t *pgdat, struct scan_control *sc) +{ + unsigned long file; + struct lruvec *target_lruvec; + + target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat); + + /* + * Flush the memory cgroup stats, so that we read accurate per-memcg + * lruvec stats for heuristics. + */ + mem_cgroup_flush_stats(); + + /* + * Determine the scan balance between anon and file LRUs. + */ + spin_lock_irq(&target_lruvec->lru_lock); + sc->anon_cost = target_lruvec->anon_cost; + sc->file_cost = target_lruvec->file_cost; + spin_unlock_irq(&target_lruvec->lru_lock); + + /* + * Target desirable inactive:active list ratios for the anon + * and file LRU lists. + */ + if (!sc->force_deactivate) { + unsigned long refaults; + + refaults = lruvec_page_state(target_lruvec, + WORKINGSET_ACTIVATE_ANON); + if (refaults != target_lruvec->refaults[0] || + inactive_is_low(target_lruvec, LRU_INACTIVE_ANON)) + sc->may_deactivate |= DEACTIVATE_ANON; + else + sc->may_deactivate &= ~DEACTIVATE_ANON; + + /* + * When refaults are being observed, it means a new + * workingset is being established. Deactivate to get + * rid of any stale active pages quickly. + */ + refaults = lruvec_page_state(target_lruvec, + WORKINGSET_ACTIVATE_FILE); + if (refaults != target_lruvec->refaults[1] || + inactive_is_low(target_lruvec, LRU_INACTIVE_FILE)) + sc->may_deactivate |= DEACTIVATE_FILE; + else + sc->may_deactivate &= ~DEACTIVATE_FILE; + } else + sc->may_deactivate = DEACTIVATE_ANON | DEACTIVATE_FILE; + + /* + * If we have plenty of inactive file pages that aren't + * thrashing, try to reclaim those first before touching + * anonymous pages. + */ + file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE); + if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE)) + sc->cache_trim_mode = 1; + else + sc->cache_trim_mode = 0; + + /* + * Prevent the reclaimer from falling into the cache trap: as + * cache pages start out inactive, every cache fault will tip + * the scan balance towards the file LRU. And as the file LRU + * shrinks, so does the window for rotation from references. + * This means we have a runaway feedback loop where a tiny + * thrashing file LRU becomes infinitely more attractive than + * anon pages. Try to detect this based on file LRU size. + */ + if (!cgroup_reclaim(sc)) { + unsigned long total_high_wmark = 0; + unsigned long free, anon; + int z; + + free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES); + file = node_page_state(pgdat, NR_ACTIVE_FILE) + + node_page_state(pgdat, NR_INACTIVE_FILE); + + for (z = 0; z < MAX_NR_ZONES; z++) { + struct zone *zone = &pgdat->node_zones[z]; + + if (!managed_zone(zone)) + continue; + + total_high_wmark += high_wmark_pages(zone); + } + + /* + * Consider anon: if that's low too, this isn't a + * runaway file reclaim problem, but rather just + * extreme pressure. Reclaim as per usual then. + */ + anon = node_page_state(pgdat, NR_INACTIVE_ANON); + + sc->file_is_tiny = + file + free <= total_high_wmark && + !(sc->may_deactivate & DEACTIVATE_ANON) && + anon >> sc->priority; + } +} + /* * Determine how aggressively the anon and file LRU lists should be * scanned. The relative value of each set of LRU lists is determined @@ -3186,109 +3289,16 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) unsigned long nr_reclaimed, nr_scanned; struct lruvec *target_lruvec; bool reclaimable = false; - unsigned long file; target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat); again: - /* - * Flush the memory cgroup stats, so that we read accurate per-memcg - * lruvec stats for heuristics. - */ - mem_cgroup_flush_stats(); - memset(&sc->nr, 0, sizeof(sc->nr)); nr_reclaimed = sc->nr_reclaimed; nr_scanned = sc->nr_scanned; - /* - * Determine the scan balance between anon and file LRUs. - */ - spin_lock_irq(&target_lruvec->lru_lock); - sc->anon_cost = target_lruvec->anon_cost; - sc->file_cost = target_lruvec->file_cost; - spin_unlock_irq(&target_lruvec->lru_lock); - - /* - * Target desirable inactive:active list ratios for the anon - * and file LRU lists. - */ - if (!sc->force_deactivate) { - unsigned long refaults; - - refaults = lruvec_page_state(target_lruvec, - WORKINGSET_ACTIVATE_ANON); - if (refaults != target_lruvec->refaults[0] || - inactive_is_low(target_lruvec, LRU_INACTIVE_ANON)) - sc->may_deactivate |= DEACTIVATE_ANON; - else - sc->may_deactivate &= ~DEACTIVATE_ANON; - - /* - * When refaults are being observed, it means a new - * workingset is being established. Deactivate to get - * rid of any stale active pages quickly. - */ - refaults = lruvec_page_state(target_lruvec, - WORKINGSET_ACTIVATE_FILE); - if (refaults != target_lruvec->refaults[1] || - inactive_is_low(target_lruvec, LRU_INACTIVE_FILE)) - sc->may_deactivate |= DEACTIVATE_FILE; - else - sc->may_deactivate &= ~DEACTIVATE_FILE; - } else - sc->may_deactivate = DEACTIVATE_ANON | DEACTIVATE_FILE; - - /* - * If we have plenty of inactive file pages that aren't - * thrashing, try to reclaim those first before touching - * anonymous pages. - */ - file = lruvec_page_state(target_lruvec, NR_INACTIVE_FILE); - if (file >> sc->priority && !(sc->may_deactivate & DEACTIVATE_FILE)) - sc->cache_trim_mode = 1; - else - sc->cache_trim_mode = 0; - - /* - * Prevent the reclaimer from falling into the cache trap: as - * cache pages start out inactive, every cache fault will tip - * the scan balance towards the file LRU. And as the file LRU - * shrinks, so does the window for rotation from references. - * This means we have a runaway feedback loop where a tiny - * thrashing file LRU becomes infinitely more attractive than - * anon pages. Try to detect this based on file LRU size. - */ - if (!cgroup_reclaim(sc)) { - unsigned long total_high_wmark = 0; - unsigned long free, anon; - int z; - - free = sum_zone_node_page_state(pgdat->node_id, NR_FREE_PAGES); - file = node_page_state(pgdat, NR_ACTIVE_FILE) + - node_page_state(pgdat, NR_INACTIVE_FILE); - - for (z = 0; z < MAX_NR_ZONES; z++) { - struct zone *zone = &pgdat->node_zones[z]; - if (!managed_zone(zone)) - continue; - - total_high_wmark += high_wmark_pages(zone); - } - - /* - * Consider anon: if that's low too, this isn't a - * runaway file reclaim problem, but rather just - * extreme pressure. Reclaim as per usual then. - */ - anon = node_page_state(pgdat, NR_INACTIVE_ANON); - - sc->file_is_tiny = - file + free <= total_high_wmark && - !(sc->may_deactivate & DEACTIVATE_ANON) && - anon >> sc->priority; - } + prepare_scan_count(pgdat, sc); shrink_node_memcgs(pgdat, sc);