From patchwork Tue Dec 22 05:20:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alex Shi X-Patchwork-Id: 11985865 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT 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 A178FC433E0 for ; Tue, 22 Dec 2020 05:21:09 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 281BE23124 for ; Tue, 22 Dec 2020 05:21:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 281BE23124 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 109286B009C; Tue, 22 Dec 2020 00:21:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0B8228D0009; Tue, 22 Dec 2020 00:21:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F36F96B009D; Tue, 22 Dec 2020 00:21:06 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0087.hostedemail.com [216.40.44.87]) by kanga.kvack.org (Postfix) with ESMTP id D5CA28D0009 for ; Tue, 22 Dec 2020 00:21:06 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id A67781EE6 for ; Tue, 22 Dec 2020 05:21:06 +0000 (UTC) X-FDA: 77619769332.28.berry90_521582c2745d Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id 782E46C33 for ; Tue, 22 Dec 2020 05:21:06 +0000 (UTC) X-HE-Tag: berry90_521582c2745d X-Filterd-Recvd-Size: 2578 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Tue, 22 Dec 2020 05:21:05 +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=e01e01424;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0UJPqUQy_1608614460; Received: from aliy80.localdomain(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0UJPqUQy_1608614460) by smtp.aliyun-inc.com(127.0.0.1); Tue, 22 Dec 2020 13:21:00 +0800 From: Alex Shi To: hughd@google.com Cc: Johannes Weiner , Michal Hocko , Vladimir Davydov , Andrew Morton , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/3] mm/memcg: revise the using condition of lock_page_lruvec function series Date: Tue, 22 Dec 2020 13:20:51 +0800 Message-Id: <1608614453-10739-1-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 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: lock_page_lruvec() and its variants are safe to use under the same conditions as commit_charge(): add lock_page_memcg() to the comment. Polished with Hugh Dickins' suggestions, thanks! 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: cgroups@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/memcontrol.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b80328f52fb4..8d400efc81b9 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1345,10 +1345,11 @@ void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page) * lock_page_lruvec - lock and return lruvec for a given page. * @page: the page * - * This series functions should be used in either conditions: - * PageLRU is cleared or unset - * or page->_refcount is zero - * or page is locked. + * These functions are safe to use under any of the following conditions: + * - page locked + * - PageLRU cleared + * - lock_page_memcg() + * - page->_refcount is zero */ struct lruvec *lock_page_lruvec(struct page *page) {