From patchwork Thu Sep 24 03:28:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Shi X-Patchwork-Id: 11795987 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 9B4BA92C for ; Thu, 24 Sep 2020 03:28:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5A3582388A for ; Thu, 24 Sep 2020 03:28:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5A3582388A 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 1C6C8900002; Wed, 23 Sep 2020 23:28:49 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id EE42E900005; Wed, 23 Sep 2020 23:28:48 -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 95945900002; Wed, 23 Sep 2020 23:28:48 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0148.hostedemail.com [216.40.44.148]) by kanga.kvack.org (Postfix) with ESMTP id 7AAA1900003 for ; Wed, 23 Sep 2020 23:28:48 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 49C9C3637 for ; Thu, 24 Sep 2020 03:28:48 +0000 (UTC) X-FDA: 77296523136.14.skirt84_3a03eb22715b Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin14.hostedemail.com (Postfix) with ESMTP id 2ACD218229818 for ; Thu, 24 Sep 2020 03:28:48 +0000 (UTC) X-Spam-Summary: 1,0,0,df47613db122cfe4,d41d8cd98f00b204,alex.shi@linux.alibaba.com,,RULES_HIT:41:69:355:379:541:800:960:968:973:988:989:1260:1261:1345:1359:1431:1437:1534:1542:1711:1730:1747:1777:1792:2198:2199:2380:2393:2559:2562:2897:3138:3139:3140:3141:3142:3353:3865:3866:3867:3868:3870:3871:3872:4321:5007:6119:6261:6737:6738:8957:9040:9592:10004:11026:11232:11473:11638:11639:11658:11914:12043:12048:12296:12297:12438:12555:12895:12986:13846:14096:14181:14394:14721:14915:21060:21080:21451:21627:21990:30054:30070:30079,0,RBL:115.124.30.56:@linux.alibaba.com:.lbl8.mailshell.net-64.201.201.201 62.20.2.100;04yrim1tfohe8xyjirsntrubqdp39ycuuea3jgwekgcs6m8wdzsrtrkjycqbtiw.gw6eiq1decb9ggmbjj9e4a4ushdkxpyw4xomq6w3oqej8g6cms51yu1yi7fohus.a-lbl8.mailshell.net-223.238.255.100,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: skirt84_3a03eb22715b X-Filterd-Recvd-Size: 4142 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Thu, 24 Sep 2020 03:28:46 +0000 (UTC) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R861e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=24;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 11:28:42 +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: "Kirill A. Shutemov" , Vlastimil Babka Subject: [PATCH v19 13/20] mm/mlock: remove lru_lock on TestClearPageMlocked Date: Thu, 24 Sep 2020 11:28:28 +0800 Message-Id: <1600918115-22007-14-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: In the func munlock_vma_page, comments mentained lru_lock needed for serialization with split_huge_pages. But the page must be PageLocked as well as pages in split_huge_page series funcs. Thus the PageLocked is enough to serialize both funcs. Further more, Hugh Dickins pointed: before splitting in split_huge_page_to_list, the page was unmap_page() to remove pmd/ptes which protect the page from munlock. Thus, no needs to guard __split_huge_page_tail for mlock clean, just keep the lru_lock there for isolation purpose. LKP found a preempt issue on __mod_zone_page_state which need change to mod_zone_page_state. Thanks! Signed-off-by: Alex Shi Acked-by: Hugh Dickins Cc: Kirill A. Shutemov Cc: Vlastimil Babka Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/mlock.c | 26 +++++--------------------- 1 file changed, 5 insertions(+), 21 deletions(-) diff --git a/mm/mlock.c b/mm/mlock.c index 884b1216da6a..796c726a0407 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -187,40 +187,24 @@ static void __munlock_isolation_failed(struct page *page) unsigned int munlock_vma_page(struct page *page) { int nr_pages; - pg_data_t *pgdat = page_pgdat(page); /* For try_to_munlock() and to serialize with page migration */ BUG_ON(!PageLocked(page)); - VM_BUG_ON_PAGE(PageTail(page), page); - /* - * Serialize with any parallel __split_huge_page_refcount() which - * might otherwise copy PageMlocked to part of the tail pages before - * we clear it in the head page. It also stabilizes thp_nr_pages(). - */ - spin_lock_irq(&pgdat->lru_lock); - if (!TestClearPageMlocked(page)) { /* Potentially, PTE-mapped THP: do not skip the rest PTEs */ - nr_pages = 1; - goto unlock_out; + return 0; } nr_pages = thp_nr_pages(page); - __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); + mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); - if (__munlock_isolate_lru_page(page, true)) { - spin_unlock_irq(&pgdat->lru_lock); + if (!isolate_lru_page(page)) __munlock_isolated_page(page); - goto out; - } - __munlock_isolation_failed(page); - -unlock_out: - spin_unlock_irq(&pgdat->lru_lock); + else + __munlock_isolation_failed(page); -out: return nr_pages - 1; }