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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 7AD97C432C3 for ; Sun, 1 Dec 2019 01:55:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2FB0A206E1 for ; Sun, 1 Dec 2019 01:55:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="KBw6AmoC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2FB0A206E1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D4AA86B0330; Sat, 30 Nov 2019 20:55:42 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CD48D6B0332; Sat, 30 Nov 2019 20:55:42 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B9C426B0333; Sat, 30 Nov 2019 20:55:42 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0099.hostedemail.com [216.40.44.99]) by kanga.kvack.org (Postfix) with ESMTP id A190F6B0330 for ; Sat, 30 Nov 2019 20:55:42 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 59B2D40F1 for ; Sun, 1 Dec 2019 01:55:42 +0000 (UTC) X-FDA: 76214906124.17.wound04_31c4c9f59b132 X-HE-Tag: wound04_31c4c9f59b132 X-Filterd-Recvd-Size: 7305 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf33.hostedemail.com (Postfix) with ESMTP for ; Sun, 1 Dec 2019 01:55:41 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 109902231B; Sun, 1 Dec 2019 01:55:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575165341; bh=gdiOj1wpH2wQAl9O3YzBOZ9dYBjMAinnZrXYepoooxo=; h=Date:From:To:Subject:From; b=KBw6AmoCTo4QQYiBRBswHLqRd7aX3FKhSWDxTrNC1wlW29vLwezcWnZvtghrFD1So vLwAo2sI3+M4aJMqZ/GQIgyx0KZHuUQDzMAeqj6w2LUT66QYxR2S64JL/371XGSrTa ceU0uqXI/khPKvw/XslZNzouGAPd+y6stdAwZ4dU= Date: Sat, 30 Nov 2019 17:55:40 -0800 From: akpm@linux-foundation.org To: akpm@linux-foundation.org, guro@fb.com, hannes@cmpxchg.org, linux-mm@kvack.org, mhocko@suse.com, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 107/158] mm: vmscan: naming fixes: global_reclaim() and sane_reclaim() Message-ID: <20191201015540.IivK3zfAf%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 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: Johannes Weiner Subject: mm: vmscan: naming fixes: global_reclaim() and sane_reclaim() 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()". Link: http://lkml.kernel.org/r/20191022144803.302233-5-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Reviewed-by: Roman Gushchin Acked-by: Michal Hocko Signed-off-by: Andrew Morton --- mm/vmscan.c | 38 ++++++++++++++++++-------------------- 1 file changed, 18 insertions(+), 20 deletions(-) --- a/mm/vmscan.c~mm-vmscan-naming-fixes-global_reclaim-and-sane_reclaim +++ a/mm/vmscan.c @@ -239,13 +239,13 @@ static void unregister_memcg_shrinker(st up_write(&shrinker_rwsem); } -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; } /** - * sane_reclaim - is the usual dirty throttling mechanism operational? + * writeback_throttling_sane - is the usual dirty throttling mechanism available? * @sc: scan_control in question * * The normal page dirty throttling mechanism in balance_dirty_pages() is @@ -257,11 +257,9 @@ static bool global_reclaim(struct scan_c * This function tests whether the vmscan currently in progress can assume * 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 = 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(st { } -static bool global_reclaim(struct scan_control *sc) +static bool cgroup_reclaim(struct scan_control *sc) { - return true; + return false; } -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(st goto activate_locked; /* 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 pgli if (current_is_kswapd()) return 0; - if (!sane_reclaim(sc)) + if (!writeback_throttling_sane(sc)) return 0; if (file) { @@ -1971,7 +1969,7 @@ shrink_inactive_list(unsigned long nr_to reclaim_stat->recent_scanned[file] += nr_taken; item = 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 spin_lock_irq(&pgdat->lru_lock); item = 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] += stat.nr_activate[0]; @@ -2309,7 +2307,7 @@ static void get_scan_count(struct lruvec * using the memory controller's swap limit feature would be * too expensive. */ - if (!global_reclaim(sc) && !swappiness) { + if (cgroup_reclaim(sc) && !swappiness) { scan_balance = SCAN_FILE; goto out; } @@ -2333,7 +2331,7 @@ static void get_scan_count(struct lruvec * 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 pgl * abort proportional reclaim if either the file or anon lru has already * dropped to zero at the first pass. */ - scan_adjusted = (global_reclaim(sc) && !current_is_kswapd() && + scan_adjusted = (!cgroup_reclaim(sc) && !current_is_kswapd() && sc->priority == DEF_PRIORITY); blk_start_plug(&plug); @@ -2853,7 +2851,7 @@ static bool shrink_node(pg_data_t *pgdat * 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 == sc->nr.congested) set_memcg_congestion(pgdat, root, true); @@ -2948,7 +2946,7 @@ static void shrink_zones(struct zonelist * 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_page retry: delayacct_freepages_start(); - if (global_reclaim(sc)) + if (!cgroup_reclaim(sc)) __count_zid_vm_events(ALLOCSTALL, sc->reclaim_idx, 1); do { _