From patchwork Mon Mar 2 11:00:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Shi X-Patchwork-Id: 11415287 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9205D138D for ; Mon, 2 Mar 2020 11:01:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5D0A32468E for ; Mon, 2 Mar 2020 11:01:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5D0A32468E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 952A96B0037; Mon, 2 Mar 2020 06:01:16 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 903036B006C; Mon, 2 Mar 2020 06:01:16 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7A2996B006E; Mon, 2 Mar 2020 06:01:16 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0141.hostedemail.com [216.40.44.141]) by kanga.kvack.org (Postfix) with ESMTP id 5B0DD6B0037 for ; Mon, 2 Mar 2020 06:01:16 -0500 (EST) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 45038180AD801 for ; Mon, 2 Mar 2020 11:01:16 +0000 (UTC) X-FDA: 76550130552.18.sink12_7f521336eb12a X-Spam-Summary: 2,0,0,4c407320a69eaab4,d41d8cd98f00b204,alex.shi@linux.alibaba.com,,RULES_HIT:2:41:69:355:379:541:800:960:966:973:988:989:1260:1261:1345:1359:1431:1437:1535:1605:1730:1747:1777:1792:2196:2198:2199:2200:2393:2553:2559:2562:2693:2731:2895:2898:2899:3138:3139:3140:3141:3142:3369:3865:3867:3868:3870:3871:3872:3874:4049:4118:4250:4321:4385:4605:5007:6119:6261:6737:8603:8957:9010:9592:10004:11026:11232:11473:11658:11914:12043:12048:12291:12296:12297:12438:12555:12683:12895:12986:13846:14394:14915:21060:21080:21451:21627:21987:21990:30012:30054:30070:30090,0,RBL:115.124.30.42:@linux.alibaba.com:.lbl8.mailshell.net-64.201.201.201 62.20.2.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: sink12_7f521336eb12a X-Filterd-Recvd-Size: 7774 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Mon, 2 Mar 2020 11:01:14 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=14;SR=0;TI=SMTPD_---0TrQzvOy_1583146856; Received: from localhost(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0TrQzvOy_1583146856) by smtp.aliyun-inc.com(127.0.0.1); Mon, 02 Mar 2020 19:00:57 +0800 From: Alex Shi To: cgroups@vger.kernel.org, akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, yang.shi@linux.alibaba.com, willy@infradead.org, hannes@cmpxchg.org, lkp@intel.com Cc: Alex Shi , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v9 08/20] mm/lru: add page isolation precondition in __isolate_lru_page Date: Mon, 2 Mar 2020 19:00:18 +0800 Message-Id: <1583146830-169516-9-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1583146830-169516-1-git-send-email-alex.shi@linux.alibaba.com> References: <1583146830-169516-1-git-send-email-alex.shi@linux.alibaba.com> 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: Johannes Weiner has suggested: " So here is a crazy idea that may be worth exploring: Right now, pgdat->lru_lock protects both PageLRU *and* the lruvec's linked list. Can we make PageLRU atomic and use it to stabilize the lru_lock instead, and then use the lru_lock only serialize list operations? ... " Yes, this patch is doing so on __isolate_lru_page which is the core page isolation func in compaction and shrinking path. This patch move clear page lru action before compaction getting lru_lock, makes it as a necessary condition for page isolation. Hence, PageLRU may be cleared druing shrink_inactive_list path for isolation reason. If so, we can skip that page's in reclaim. It's a preparation for later per memcg lru_lock change. Suggested-by: Johannes Weiner Signed-off-by: Alex Shi Cc: Andrew Morton Cc: Matthew Wilcox Cc: Hugh Dickins Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org --- include/linux/swap.h | 2 +- mm/compaction.c | 25 +++++++++++++++++-------- mm/vmscan.c | 48 ++++++++++++++++++++++++++---------------------- 3 files changed, 44 insertions(+), 31 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index c555e8f161ad..69f0794f1da3 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -351,7 +351,7 @@ extern void lru_cache_add_active_or_unevictable(struct page *page, extern unsigned long zone_reclaimable_pages(struct zone *zone); extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *mask); -extern int __isolate_lru_page(struct page *page, isolate_mode_t mode); +extern int __isolate_lru_page_prepare(struct page *page, isolate_mode_t mode); extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, unsigned long nr_pages, gfp_t gfp_mask, diff --git a/mm/compaction.c b/mm/compaction.c index 672d3c78c6ab..1baba328d089 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -948,6 +948,23 @@ static bool too_many_isolated(pg_data_t *pgdat) if (!(cc->gfp_mask & __GFP_FS) && page_mapping(page)) goto isolate_fail; + if (__isolate_lru_page_prepare(page, isolate_mode) != 0) + goto isolate_fail; + + /* + * Be careful not to clear PageLRU until after we're + * sure the page is not being freed elsewhere -- the + * page release code relies on it. + */ + if (unlikely(!get_page_unless_zero(page))) + goto isolate_fail; + + /* Try isolate the page */ + if (!TestClearPageLRU(page)) { + put_page(page); + goto isolate_fail; + } + /* If we already hold the lock, we can skip some rechecking */ if (!locked) { locked = compact_lock_irqsave(&pgdat->lru_lock, @@ -960,10 +977,6 @@ static bool too_many_isolated(pg_data_t *pgdat) goto isolate_abort; } - /* Recheck PageLRU and PageCompound under lock */ - if (!PageLRU(page)) - goto isolate_fail; - /* * Page become compound since the non-locked check, * and it's on LRU. It can only be a THP so the order @@ -977,10 +990,6 @@ static bool too_many_isolated(pg_data_t *pgdat) lruvec = mem_cgroup_page_lruvec(page, pgdat); - /* Try isolate the page */ - if (__isolate_lru_page(page, isolate_mode) != 0) - goto isolate_fail; - VM_BUG_ON_PAGE(PageCompound(page), page); /* Successfully isolated */ diff --git a/mm/vmscan.c b/mm/vmscan.c index 8958454d50fe..bc2ec3fe4f48 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1522,20 +1522,20 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, * * returns 0 on success, -ve errno on failure. */ -int __isolate_lru_page(struct page *page, isolate_mode_t mode) +int __isolate_lru_page_prepare(struct page *page, isolate_mode_t mode) { int ret = -EINVAL; - /* Only take pages on the LRU. */ - if (!PageLRU(page)) - return ret; - /* Compaction should not handle unevictable pages but CMA can do so */ if (PageUnevictable(page) && !(mode & ISOLATE_UNEVICTABLE)) return ret; ret = -EBUSY; + /* Only take pages on the LRU. */ + if (!PageLRU(page)) + return ret; + /* * To minimise LRU disruption, the caller can indicate that it only * wants to isolate pages it will be able to operate on without @@ -1576,20 +1576,9 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode) if ((mode & ISOLATE_UNMAPPED) && page_mapped(page)) return ret; - if (likely(get_page_unless_zero(page))) { - /* - * Be careful not to clear PageLRU until after we're - * sure the page is not being freed elsewhere -- the - * page release code relies on it. - */ - ClearPageLRU(page); - ret = 0; - } - - return ret; + return 0; } - /* * Update LRU sizes after isolating pages. The LRU size updates must * be complete before mem_cgroup_update_lru_size due to a santity check. @@ -1653,8 +1642,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, page = lru_to_page(src); prefetchw_prev_lru_page(page, src, flags); - VM_BUG_ON_PAGE(!PageLRU(page), page); - nr_pages = compound_nr(page); total_scan += nr_pages; @@ -1675,17 +1662,34 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan, * only when the page is being freed somewhere else. */ scan += nr_pages; - switch (__isolate_lru_page(page, mode)) { + switch (__isolate_lru_page_prepare(page, mode)) { case 0: + /* + * Be careful not to clear PageLRU until after we're + * sure the page is not being freed elsewhere -- the + * page release code relies on it. + */ + if (unlikely(!get_page_unless_zero(page))) + goto busy; + + if (!TestClearPageLRU(page)) { + /* + * This page may in other isolation path, + * but we still hold lru_lock. + */ + put_page(page); + goto busy; + } + nr_taken += nr_pages; nr_zone_taken[page_zonenum(page)] += nr_pages; list_move(&page->lru, dst); break; - +busy: case -EBUSY: /* else it is being freed elsewhere */ list_move(&page->lru, src); - continue; + break; default: BUG();