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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 4BF68CA9EA0 for ; Tue, 22 Oct 2019 14:48:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F3FE621783 for ; Tue, 22 Oct 2019 14:48:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=cmpxchg-org.20150623.gappssmtp.com header.i=@cmpxchg-org.20150623.gappssmtp.com header.b="VeyPNpse" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F3FE621783 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=cmpxchg.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EA9706B000A; Tue, 22 Oct 2019 10:48:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E842D6B000C; Tue, 22 Oct 2019 10:48:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D9B4C6B000D; Tue, 22 Oct 2019 10:48:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0172.hostedemail.com [216.40.44.172]) by kanga.kvack.org (Postfix) with ESMTP id B91BD6B000A for ; Tue, 22 Oct 2019 10:48:20 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 651F5181AEF3F for ; Tue, 22 Oct 2019 14:48:20 +0000 (UTC) X-FDA: 76071701160.28.ray04_65dcaef0ed144 X-HE-Tag: ray04_65dcaef0ed144 X-Filterd-Recvd-Size: 9100 Received: from mail-qt1-f194.google.com (mail-qt1-f194.google.com [209.85.160.194]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Tue, 22 Oct 2019 14:48:19 +0000 (UTC) Received: by mail-qt1-f194.google.com with SMTP id o25so13758592qtr.5 for ; Tue, 22 Oct 2019 07:48:19 -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=54i+z1wfPwz6/cGLiUfokNvMUBs/QmsNtuItwhjfY2I=; b=VeyPNpsexL0QFkwSfvrTR+ipseMK3B6GkLGCh7t5KGPNh0aMLaYY4TWUiEkgaDu6sD OkqHdMhcpIvf5XAGg/oS8FJjjmUpM6xU7YpSL3bUeqIvvhVMb5cC3eV3DewVSbLjNStD 9hGN9zzHYGIgW7xx0P59N7oMLQTufgOsE1gjmjXMZVI47+Zkyxj31tmPrn8qjtbRAFPh vNFBmq6PWAVVO0YuBbdhsLwignvBhDRkChbOK6E5kx0O2EhLLaGU1GycTyplz//xMOhi DEIK+UTUiUZN6jWWk5xd9koF4vwGVJUX9DZcU5arHIMdyseCVVORi9OuYlO1srYyED4+ O6JA== 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=54i+z1wfPwz6/cGLiUfokNvMUBs/QmsNtuItwhjfY2I=; b=mThmR50bQv3R1XWoElsxpXUvM3tmQMaNxZdEf3PYTFJ29qfgfy0kN/XJhdsJdN9lhN iaIFDnyZ5tHf+O0GaS1fDb7GRLMawaVso2xGc9cdhbAE1F7vYOQJyqDvxUll1xwbkCe/ UKhMeL/q8IWtW43iNMFabK1Yv1OFaoTzITnMLtaodfD8NKxy9/WlS/8JuK89a89FBuI4 1STQLXjL1h9k4u0mJLzuj9vk2sgv4XMsvhk1F1bwup4L08MULckLHZH6euxB/w0w+/jc umvz2mSVpXUsxcHS/IUWE9JW7Ga2cUcAdsERsfgfnKmPTyLModbNLX/Ad5NbM6aNrx4o JvPA== X-Gm-Message-State: APjAAAWod4hAsGT8JZq6mjVxTYk1h1WT7FUo3axYWEClgKhlNGzXkE7W 07isjXuzrvTsLAtVKL1aYYmaPw== X-Google-Smtp-Source: APXvYqxUIOCsaOjFLF5giMe1ZXcyXhEJn1Gw5IIrOkv2mgKxObwAUB99LeseVc6rptgLFSj6NnGlZw== X-Received: by 2002:ac8:73cf:: with SMTP id v15mr3631553qtp.310.1571755699119; Tue, 22 Oct 2019 07:48:19 -0700 (PDT) Received: from localhost ([2620:10d:c091:500::3:10ad]) by smtp.gmail.com with ESMTPSA id q16sm7131372qke.22.2019.10.22.07.48.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Oct 2019 07:48:18 -0700 (PDT) From: Johannes Weiner To: Andrew Morton Cc: Michal Hocko , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: [PATCH 4/8] mm: vmscan: naming fixes: global_reclaim() and sane_reclaim() Date: Tue, 22 Oct 2019 10:47:59 -0400 Message-Id: <20191022144803.302233-5-hannes@cmpxchg.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191022144803.302233-1-hannes@cmpxchg.org> References: <20191022144803.302233-1-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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: Seven years after introducing the global_reclaim() function, I still have to double take when reading a callsite. I don't know how others do it, this is a terrible name. Invert the meaning and rename it to cgroup_reclaim(). [ After all, "global reclaim" is just regular reclaim invoked from the page allocator. It's reclaim on behalf of a cgroup limit that is a special case of reclaim, and should be explicit - not the reverse. ] sane_reclaim() isn't very descriptive either: it tests whether we can use the regular writeback throttling - available during regular page reclaim or cgroup2 limit reclaim - or need to use the broken wait_on_page_writeback() method. Use "writeback_throttling_sane()". Signed-off-by: Johannes Weiner --- mm/vmscan.c | 38 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 20 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 622b77488144..302dad112f75 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -239,13 +239,13 @@ static void unregister_memcg_shrinker(struct shrink= er *shrinker) up_write(&shrinker_rwsem); } =20 -static bool global_reclaim(struct scan_control *sc) +static bool cgroup_reclaim(struct scan_control *sc) { - return !sc->target_mem_cgroup; + return sc->target_mem_cgroup; } =20 /** - * sane_reclaim - is the usual dirty throttling mechanism operational? + * writeback_throttling_sane - is the usual dirty throttling mechanism a= vailable? * @sc: scan_control in question * * The normal page dirty throttling mechanism in balance_dirty_pages() i= s @@ -257,11 +257,9 @@ static bool global_reclaim(struct scan_control *sc) * This function tests whether the vmscan currently in progress can assu= me * that the normal dirty throttling mechanism is operational. */ -static bool sane_reclaim(struct scan_control *sc) +static bool writeback_throttling_sane(struct scan_control *sc) { - struct mem_cgroup *memcg =3D sc->target_mem_cgroup; - - if (!memcg) + if (!cgroup_reclaim(sc)) return true; #ifdef CONFIG_CGROUP_WRITEBACK if (cgroup_subsys_on_dfl(memory_cgrp_subsys)) @@ -302,12 +300,12 @@ static void unregister_memcg_shrinker(struct shrink= er *shrinker) { } =20 -static bool global_reclaim(struct scan_control *sc) +static bool cgroup_reclaim(struct scan_control *sc) { - return true; + return false; } =20 -static bool sane_reclaim(struct scan_control *sc) +static bool writeback_throttling_sane(struct scan_control *sc) { return true; } @@ -1227,7 +1225,7 @@ static unsigned long shrink_page_list(struct list_h= ead *page_list, goto activate_locked; =20 /* Case 2 above */ - } else if (sane_reclaim(sc) || + } else if (writeback_throttling_sane(sc) || !PageReclaim(page) || !may_enter_fs) { /* * This is slightly racy - end_page_writeback() @@ -1821,7 +1819,7 @@ static int too_many_isolated(struct pglist_data *pg= dat, int file, if (current_is_kswapd()) return 0; =20 - if (!sane_reclaim(sc)) + if (!writeback_throttling_sane(sc)) return 0; =20 if (file) { @@ -1971,7 +1969,7 @@ shrink_inactive_list(unsigned long nr_to_scan, stru= ct lruvec *lruvec, reclaim_stat->recent_scanned[file] +=3D nr_taken; =20 item =3D current_is_kswapd() ? PGSCAN_KSWAPD : PGSCAN_DIRECT; - if (global_reclaim(sc)) + if (!cgroup_reclaim(sc)) __count_vm_events(item, nr_scanned); __count_memcg_events(lruvec_memcg(lruvec), item, nr_scanned); spin_unlock_irq(&pgdat->lru_lock); @@ -1985,7 +1983,7 @@ shrink_inactive_list(unsigned long nr_to_scan, stru= ct lruvec *lruvec, spin_lock_irq(&pgdat->lru_lock); =20 item =3D current_is_kswapd() ? PGSTEAL_KSWAPD : PGSTEAL_DIRECT; - if (global_reclaim(sc)) + if (!cgroup_reclaim(sc)) __count_vm_events(item, nr_reclaimed); __count_memcg_events(lruvec_memcg(lruvec), item, nr_reclaimed); reclaim_stat->recent_rotated[0] +=3D stat.nr_activate[0]; @@ -2309,7 +2307,7 @@ static void get_scan_count(struct lruvec *lruvec, s= truct mem_cgroup *memcg, * using the memory controller's swap limit feature would be * too expensive. */ - if (!global_reclaim(sc) && !swappiness) { + if (cgroup_reclaim(sc) && !swappiness) { scan_balance =3D SCAN_FILE; goto out; } @@ -2333,7 +2331,7 @@ static void get_scan_count(struct lruvec *lruvec, s= truct mem_cgroup *memcg, * thrashing file LRU becomes infinitely more attractive than * anon pages. Try to detect this based on file LRU size. */ - if (global_reclaim(sc)) { + if (!cgroup_reclaim(sc)) { unsigned long pgdatfile; unsigned long pgdatfree; int z; @@ -2564,7 +2562,7 @@ static void shrink_node_memcg(struct pglist_data *p= gdat, struct mem_cgroup *memc * abort proportional reclaim if either the file or anon lru has alread= y * dropped to zero at the first pass. */ - scan_adjusted =3D (global_reclaim(sc) && !current_is_kswapd() && + scan_adjusted =3D (!cgroup_reclaim(sc) && !current_is_kswapd() && sc->priority =3D=3D DEF_PRIORITY); =20 blk_start_plug(&plug); @@ -2853,7 +2851,7 @@ static bool shrink_node(pg_data_t *pgdat, struct sc= an_control *sc) * Legacy memcg will stall in page writeback so avoid forcibly * stalling in wait_iff_congested(). */ - if (!global_reclaim(sc) && sane_reclaim(sc) && + if (cgroup_reclaim(sc) && writeback_throttling_sane(sc) && sc->nr.dirty && sc->nr.dirty =3D=3D sc->nr.congested) set_memcg_congestion(pgdat, root, true); =20 @@ -2948,7 +2946,7 @@ static void shrink_zones(struct zonelist *zonelist,= struct scan_control *sc) * Take care memory controller reclaiming has small influence * to global LRU. */ - if (global_reclaim(sc)) { + if (!cgroup_reclaim(sc)) { if (!cpuset_zone_allowed(zone, GFP_KERNEL | __GFP_HARDWALL)) continue; @@ -3048,7 +3046,7 @@ static unsigned long do_try_to_free_pages(struct zo= nelist *zonelist, retry: delayacct_freepages_start(); =20 - if (global_reclaim(sc)) + if (!cgroup_reclaim(sc)) __count_zid_vm_events(ALLOCSTALL, sc->reclaim_idx, 1); =20 do { --=20 2.23.0