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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4133DC4361B for ; Tue, 15 Dec 2020 22:21:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DF46722CB9 for ; Tue, 15 Dec 2020 22:21:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF46722CB9 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 81FC76B0036; Tue, 15 Dec 2020 17:21:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7CF9E6B005D; Tue, 15 Dec 2020 17:21:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6721A6B0073; Tue, 15 Dec 2020 17:21:21 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0216.hostedemail.com [216.40.44.216]) by kanga.kvack.org (Postfix) with ESMTP id 4BB8D6B0036 for ; Tue, 15 Dec 2020 17:21:21 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 12D6A180AD81A for ; Tue, 15 Dec 2020 22:21:21 +0000 (UTC) X-FDA: 77596938762.16.honey62_5b0b0e627427 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id E8396100E6903 for ; Tue, 15 Dec 2020 22:21:20 +0000 (UTC) X-HE-Tag: honey62_5b0b0e627427 X-Filterd-Recvd-Size: 7624 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Tue, 15 Dec 2020 22:21:20 +0000 (UTC) Date: Tue, 15 Dec 2020 14:21:18 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1608070879; bh=BVx8MCtmmzSLRDN8wp4Qqb/rIkvBhWvTWbbeCe3Qf8A=; h=From:To:Subject:In-Reply-To:From; b=TJR7R7u3TsiKbUbCi70zPM28cp8q9Kt/S1bVNTUyBsCDPTKKXFsNvMKNOjwrUc6aT yT8/LcJ+5O/Q8NqV9M6skR1Wp7aQkjtVDSZDN+pFTW/1dVDVHFHkAyNyTIdlrJ3Tbw iY2oVbQENopztHv2KCe/vaaOBb9YMAJIx9BeZstY= From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, alex.shi@linux.alibaba.com, alexander.duyck@gmail.com, aryabinin@virtuozzo.com, daniel.m.jordan@oracle.com, hannes@cmpxchg.org, hughd@google.com, iamjoonsoo.kim@lge.com, jannh@google.com, khlebnikov@yandex-team.ru, kirill.shutemov@linux.intel.com, kirill@shutemov.name, linux-mm@kvack.org, mgorman@techsingularity.net, mhocko@kernel.org, mhocko@suse.com, mika.penttila@nextfour.com, minchan@kernel.org, mm-commits@vger.kernel.org, richard.weiyang@gmail.com, rong.a.chen@intel.com, shakeelb@google.com, tglx@linutronix.de, tj@kernel.org, torvalds@linux-foundation.org, vbabka@suse.cz, vdavydov.dev@gmail.com, willy@infradead.org, yang.shi@linux.alibaba.com, ying.huang@intel.com Subject: [patch 16/19] mm/swap.c: serialize memcg changes in pagevec_lru_move_fn Message-ID: <20201215222118.m_yVR3JBW%akpm@linux-foundation.org> In-Reply-To: <20201215123253.954eca9a5ef4c0d52fd381fa@linux-foundation.org> User-Agent: s-nail v14.8.16 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 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: =46rom: Alex Shi Subject: mm/swap.c: serialize memcg changes in pagevec_lru_move_fn Hugh Dickins' found a memcg change bug on original version: If we want to change the pgdat->lru_lock to memcg's lruvec lock, we have to serialize mem_cgroup_move_account during pagevec_lru_move_fn. The possible bad scenario would like: cpu 0 cpu 1 lruvec =3D mem_cgroup_page_lruvec() if (!isolate_lru_page()) mem_cgroup_move_account spin_lock_irqsave(&lruvec->lru_lock <=3D=3D wrong lock. So we need TestClearPageLRU to block isolate_lru_page(), that serializes the memcg change. and then removing the PageLRU check in move_fn callee as the consequence. __pagevec_lru_add_fn() is different from the others, because the pages it deals with are, by definition, not yet on the lru. TestClearPageLRU is not needed and would not work, so __pagevec_lru_add() goes its own way. Link: https://lkml.kernel.org/r/1604566549-62481-17-git-send-email-alex.shi= @linux.alibaba.com Reported-by: Hugh Dickins Signed-off-by: Alex Shi Acked-by: Hugh Dickins Acked-by: Johannes Weiner Acked-by: Vlastimil Babka Cc: Alexander Duyck Cc: Andrea Arcangeli Cc: Andrey Ryabinin Cc: "Chen, Rong A" Cc: Daniel Jordan Cc: "Huang, Ying" Cc: Jann Horn Cc: Joonsoo Kim Cc: Kirill A. Shutemov Cc: Kirill A. Shutemov Cc: Konstantin Khlebnikov Cc: Matthew Wilcox (Oracle) Cc: Mel Gorman Cc: Michal Hocko Cc: Michal Hocko Cc: Mika Penttil=C3=A4 Cc: Minchan Kim Cc: Shakeel Butt Cc: Tejun Heo Cc: Thomas Gleixner Cc: Vladimir Davydov Cc: Wei Yang Cc: Yang Shi Signed-off-by: Andrew Morton --- mm/swap.c | 44 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 9 deletions(-) --- a/mm/swap.c~mm-swapc-serialize-memcg-changes-in-pagevec_lru_move_fn +++ a/mm/swap.c @@ -222,8 +222,14 @@ static void pagevec_lru_move_fn(struct p spin_lock_irqsave(&pgdat->lru_lock, flags); } =20 + /* block memcg migration during page moving between lru */ + if (!TestClearPageLRU(page)) + continue; + lruvec =3D mem_cgroup_page_lruvec(page, pgdat); (*move_fn)(page, lruvec); + + SetPageLRU(page); } if (pgdat) spin_unlock_irqrestore(&pgdat->lru_lock, flags); @@ -233,7 +239,7 @@ static void pagevec_lru_move_fn(struct p =20 static void pagevec_move_tail_fn(struct page *page, struct lruvec *lruvec) { - if (PageLRU(page) && !PageUnevictable(page)) { + if (!PageUnevictable(page)) { del_page_from_lru_list(page, lruvec, page_lru(page)); ClearPageActive(page); add_page_to_lru_list_tail(page, lruvec, page_lru(page)); @@ -306,7 +312,7 @@ void lru_note_cost_page(struct page *pag =20 static void __activate_page(struct page *page, struct lruvec *lruvec) { - if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) { + if (!PageActive(page) && !PageUnevictable(page)) { int lru =3D page_lru_base_type(page); int nr_pages =3D thp_nr_pages(page); =20 @@ -362,7 +368,8 @@ static void activate_page(struct page *p =20 page =3D compound_head(page); spin_lock_irq(&pgdat->lru_lock); - __activate_page(page, mem_cgroup_page_lruvec(page, pgdat)); + if (PageLRU(page)) + __activate_page(page, mem_cgroup_page_lruvec(page, pgdat)); spin_unlock_irq(&pgdat->lru_lock); } #endif @@ -519,9 +526,6 @@ static void lru_deactivate_file_fn(struc bool active; int nr_pages =3D thp_nr_pages(page); =20 - if (!PageLRU(page)) - return; - if (PageUnevictable(page)) return; =20 @@ -562,7 +566,7 @@ static void lru_deactivate_file_fn(struc =20 static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec) { - if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) { + if (PageActive(page) && !PageUnevictable(page)) { int lru =3D page_lru_base_type(page); int nr_pages =3D thp_nr_pages(page); =20 @@ -579,7 +583,7 @@ static void lru_deactivate_fn(struct pag =20 static void lru_lazyfree_fn(struct page *page, struct lruvec *lruvec) { - if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) && + if (PageAnon(page) && PageSwapBacked(page) && !PageSwapCache(page) && !PageUnevictable(page)) { bool active =3D PageActive(page); int nr_pages =3D thp_nr_pages(page); @@ -1021,7 +1025,29 @@ static void __pagevec_lru_add_fn(struct */ void __pagevec_lru_add(struct pagevec *pvec) { - pagevec_lru_move_fn(pvec, __pagevec_lru_add_fn); + int i; + struct pglist_data *pgdat =3D NULL; + struct lruvec *lruvec; + unsigned long flags =3D 0; + + for (i =3D 0; i < pagevec_count(pvec); i++) { + struct page *page =3D pvec->pages[i]; + struct pglist_data *pagepgdat =3D page_pgdat(page); + + if (pagepgdat !=3D pgdat) { + if (pgdat) + spin_unlock_irqrestore(&pgdat->lru_lock, flags); + pgdat =3D pagepgdat; + spin_lock_irqsave(&pgdat->lru_lock, flags); + } + + lruvec =3D mem_cgroup_page_lruvec(page, pgdat); + __pagevec_lru_add_fn(page, lruvec); + } + if (pgdat) + spin_unlock_irqrestore(&pgdat->lru_lock, flags); + release_pages(pvec->pages, pvec->nr); + pagevec_reinit(pvec); } =20 /** _