From patchwork Thu Sep 24 03:28:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Shi X-Patchwork-Id: 11796007 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 E5FA51668 for ; Thu, 24 Sep 2020 03:29:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id AF75C23600 for ; Thu, 24 Sep 2020 03:29:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AF75C23600 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 4A571900010; Wed, 23 Sep 2020 23:28:55 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 42BC990000F; Wed, 23 Sep 2020 23:28:55 -0400 (EDT) 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 2318790000E; Wed, 23 Sep 2020 23:28:55 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0224.hostedemail.com [216.40.44.224]) by kanga.kvack.org (Postfix) with ESMTP id 04F4690000A for ; Wed, 23 Sep 2020 23:28:55 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id BCF608249980 for ; Thu, 24 Sep 2020 03:28:54 +0000 (UTC) X-FDA: 77296523388.03.ghost19_2b02bba2715b Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id 9DBBE28A4E8 for ; Thu, 24 Sep 2020 03:28:54 +0000 (UTC) X-Spam-Summary: 1,0,0,9f77eb73e7a3d79d,d41d8cd98f00b204,alex.shi@linux.alibaba.com,,RULES_HIT:2:41:69:355:379:541:800:960:966:967:968:973:988:989:1260:1261:1345:1359:1431:1437:1535:1605:1730:1747:1777:1792:2196:2199:2393:2525:2553:2559:2563:2682:2685:2693:2859:2898:2901:2914:2918:2933:2937:2939:2942:2945:2947:2951:2954:3022:3138:3139:3140:3141:3142:3865:3866:3867:3868:3870:3871:3872:3874:3934:3936:3938:3941:3944:3947:3950:3953:3956:3959:4049:4119:4250:4321:4385:4605:5007:6261:6737:6738:7514:7903:8603:8957:9010:9025:9592:10004:11026:11232:11473:11638:11639:11658:11914:12043:12048:12296:12297:12438:12555:12683:12895:12986:13161:13172:13229:13845:13846:14093:14096:14394:14915:21060:21080:21451:21627:21740:21809:21811:21987:21990:30012:30054:30064:30070:30090,0,RBL:115.124.30.56:@linux.alibaba.com:.lbl8.mailshell.net-62.20.2.100 64.201.201.201;04ygny8r4wp5719t3fucn3xcs8eh7yctke4fs6bekms3zscntofo5xngpj94x98.kjdzxtx9xntf8yatpszdn7xga1imtszwrnzeaedj1pwyns3etwps4gst5b68weq.r-lbl8.mai lshell.n X-HE-Tag: ghost19_2b02bba2715b X-Filterd-Recvd-Size: 8494 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Thu, 24 Sep 2020 03:28:52 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R141e4;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=23;SR=0;TI=SMTPD_---0U9w0Ss1_1600918116; Received: from aliy80.localdomain(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U9w0Ss1_1600918116) by smtp.aliyun-inc.com(127.0.0.1); Thu, 24 Sep 2020 11:28:43 +0800 From: Alex Shi To: akpm@linux-foundation.org, mgorman@techsingularity.net, tj@kernel.org, hughd@google.com, khlebnikov@yandex-team.ru, daniel.m.jordan@oracle.com, willy@infradead.org, hannes@cmpxchg.org, lkp@intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, shakeelb@google.com, iamjoonsoo.kim@lge.com, richard.weiyang@gmail.com, kirill@shutemov.name, alexander.duyck@gmail.com, rong.a.chen@intel.com, mhocko@suse.com, vdavydov.dev@gmail.com, shy828301@gmail.com, aaron.lwe@gmail.com Cc: Michal Hocko Subject: [PATCH v19 15/20] mm/lru: introduce TestClearPageLRU Date: Thu, 24 Sep 2020 11:28:30 +0800 Message-Id: <1600918115-22007-16-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1600918115-22007-1-git-send-email-alex.shi@linux.alibaba.com> References: <1600918115-22007-1-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: Currently lru_lock still guards both lru list and page's lru bit, that's ok. but if we want to use specific lruvec lock on the page, we need to pin down the page's lruvec/memcg during locking. Just taking lruvec lock first may be undermined by the page's memcg charge/migration. To fix this problem, we could clear the lru bit out of locking and use it as pin down action to block the page isolation in memcg changing. So now a standard steps of page isolation is following: 1, get_page(); #pin the page avoid to be free 2, TestClearPageLRU(); #block other isolation like memcg change 3, spin_lock on lru_lock; #serialize lru list access 4, delete page from lru list; The step 2 could be optimzed/replaced in scenarios which page is unlikely be accessed or be moved between memcgs. This patch start with the first part: TestClearPageLRU, which combines PageLRU check and ClearPageLRU into a macro func TestClearPageLRU. This function will be used as page isolation precondition to prevent other isolations some where else. Then there are may !PageLRU page on lru list, need to remove BUG() checking accordingly. There 2 rules for lru bit now: 1, the lru bit still indicate if a page on lru list, just in some temporary moment(isolating), the page may have no lru bit when it's on lru list. but the page still must be on lru list when the lru bit set. 2, have to remove lru bit before delete it from lru list. As Andrew Morton mentioned this change would dirty cacheline for page isn't on LRU. But the lost would be acceptable in Rong Chen report: https://lore.kernel.org/lkml/20200304090301.GB5972@shao2-debian/ Suggested-by: Johannes Weiner Signed-off-by: Alex Shi Acked-by: Hugh Dickins Cc: Hugh Dickins Cc: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Cc: Andrew Morton Cc: linux-kernel@vger.kernel.org Cc: cgroups@vger.kernel.org Cc: linux-mm@kvack.org --- include/linux/page-flags.h | 1 + mm/mlock.c | 3 +-- mm/vmscan.c | 39 +++++++++++++++++++-------------------- 3 files changed, 21 insertions(+), 22 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 6be1aa559b1e..9554ed1387dc 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -326,6 +326,7 @@ static inline void page_init_poison(struct page *page, size_t size) PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) + TESTCLEARFLAG(LRU, lru, PF_HEAD) PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) TESTCLEARFLAG(Active, active, PF_HEAD) PAGEFLAG(Workingset, workingset, PF_HEAD) diff --git a/mm/mlock.c b/mm/mlock.c index d487aa864e86..7b0e6334be6f 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -276,10 +276,9 @@ static void __munlock_pagevec(struct pagevec *pvec, struct zone *zone) * We already have pin from follow_page_mask() * so we can spare the get_page() here. */ - if (PageLRU(page)) { + if (TestClearPageLRU(page)) { struct lruvec *lruvec; - ClearPageLRU(page); lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page)); del_page_from_lru_list(page, lruvec, diff --git a/mm/vmscan.c b/mm/vmscan.c index 953a068b3fc7..9d06c609c60e 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1540,7 +1540,7 @@ unsigned int reclaim_clean_pages_from_list(struct zone *zone, */ int __isolate_lru_page(struct page *page, isolate_mode_t mode) { - int ret = -EINVAL; + int ret = -EBUSY; /* Only take pages on the LRU. */ if (!PageLRU(page)) @@ -1550,8 +1550,6 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode) if (PageUnevictable(page) && !(mode & ISOLATE_UNEVICTABLE)) return ret; - ret = -EBUSY; - /* * To minimise LRU disruption, the caller can indicate that it only * wants to isolate pages it will be able to operate on without @@ -1598,8 +1596,10 @@ int __isolate_lru_page(struct page *page, isolate_mode_t mode) * sure the page is not being freed elsewhere -- the * page release code relies on it. */ - ClearPageLRU(page); - ret = 0; + if (TestClearPageLRU(page)) + ret = 0; + else + put_page(page); } return ret; @@ -1665,8 +1665,6 @@ 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; @@ -1763,21 +1761,18 @@ int isolate_lru_page(struct page *page) VM_BUG_ON_PAGE(!page_count(page), page); WARN_RATELIMIT(PageTail(page), "trying to isolate tail page"); - if (PageLRU(page)) { + if (TestClearPageLRU(page)) { pg_data_t *pgdat = page_pgdat(page); struct lruvec *lruvec; - spin_lock_irq(&pgdat->lru_lock); + get_page(page); lruvec = mem_cgroup_page_lruvec(page, pgdat); - if (PageLRU(page)) { - int lru = page_lru(page); - get_page(page); - ClearPageLRU(page); - del_page_from_lru_list(page, lruvec, lru); - ret = 0; - } + spin_lock_irq(&pgdat->lru_lock); + del_page_from_lru_list(page, lruvec, page_lru(page)); spin_unlock_irq(&pgdat->lru_lock); + ret = 0; } + return ret; } @@ -4287,6 +4282,10 @@ void check_move_unevictable_pages(struct pagevec *pvec) nr_pages = thp_nr_pages(page); pgscanned += nr_pages; + /* block memcg migration during page moving between lru */ + if (!TestClearPageLRU(page)) + continue; + if (pagepgdat != pgdat) { if (pgdat) spin_unlock_irq(&pgdat->lru_lock); @@ -4295,10 +4294,7 @@ void check_move_unevictable_pages(struct pagevec *pvec) } lruvec = mem_cgroup_page_lruvec(page, pgdat); - if (!PageLRU(page) || !PageUnevictable(page)) - continue; - - if (page_evictable(page)) { + if (page_evictable(page) && PageUnevictable(page)) { enum lru_list lru = page_lru_base_type(page); VM_BUG_ON_PAGE(PageActive(page), page); @@ -4307,12 +4303,15 @@ void check_move_unevictable_pages(struct pagevec *pvec) add_page_to_lru_list(page, lruvec, lru); pgrescued += nr_pages; } + SetPageLRU(page); } if (pgdat) { __count_vm_events(UNEVICTABLE_PGRESCUED, pgrescued); __count_vm_events(UNEVICTABLE_PGSCANNED, pgscanned); spin_unlock_irq(&pgdat->lru_lock); + } else if (pgscanned) { + count_vm_events(UNEVICTABLE_PGSCANNED, pgscanned); } } EXPORT_SYMBOL_GPL(check_move_unevictable_pages);