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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=unavailable 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 72AACC3F68F for ; Wed, 25 Dec 2019 09:05:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D3B52077B for ; Wed, 25 Dec 2019 09:05:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727071AbfLYJFJ (ORCPT ); Wed, 25 Dec 2019 04:05:09 -0500 Received: from out30-57.freemail.mail.aliyun.com ([115.124.30.57]:37105 "EHLO out30-57.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726461AbfLYJFE (ORCPT ); Wed, 25 Dec 2019 04:05:04 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R891e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07487;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0TltPEgn_1577264680; Received: from localhost(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0TltPEgn_1577264680) by smtp.aliyun-inc.com(127.0.0.1); Wed, 25 Dec 2019 17:04:41 +0800 From: Alex Shi To: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.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, shakeelb@google.com, hannes@cmpxchg.org Cc: Michal Hocko , Vladimir Davydov Subject: [PATCH v7 02/10] mm/memcg: fold lru_lock in lock_page_lru Date: Wed, 25 Dec 2019 17:04:18 +0800 Message-Id: <1577264666-246071-3-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1577264666-246071-1-git-send-email-alex.shi@linux.alibaba.com> References: <1577264666-246071-1-git-send-email-alex.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >From the commit_charge's explanations and mem_cgroup_commit_charge comments, as well as call path when lrucare is ture, The lru_lock is just to guard the task migration(which would be lead to move_account) So it isn't needed when !PageLRU, and better be fold into PageLRU to reduce lock contentions. Signed-off-by: Alex Shi Cc: Johannes Weiner Cc: Michal Hocko Cc: Matthew Wilcox 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, 4 insertions(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c5b5f74cfd4d..0ad10caabc3d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2572,12 +2572,11 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages) static void lock_page_lru(struct page *page, int *isolated) { - pg_data_t *pgdat = page_pgdat(page); - - spin_lock_irq(&pgdat->lru_lock); if (PageLRU(page)) { + pg_data_t *pgdat = page_pgdat(page); struct lruvec *lruvec; + spin_lock_irq(&pgdat->lru_lock); lruvec = mem_cgroup_page_lruvec(page, pgdat); ClearPageLRU(page); del_page_from_lru_list(page, lruvec, page_lru(page)); @@ -2588,17 +2587,17 @@ static void lock_page_lru(struct page *page, int *isolated) static void unlock_page_lru(struct page *page, int isolated) { - pg_data_t *pgdat = page_pgdat(page); if (isolated) { + pg_data_t *pgdat = page_pgdat(page); struct lruvec *lruvec; lruvec = mem_cgroup_page_lruvec(page, pgdat); VM_BUG_ON_PAGE(PageLRU(page), page); SetPageLRU(page); add_page_to_lru_list(page, lruvec, page_lru(page)); + spin_unlock_irq(&pgdat->lru_lock); } - spin_unlock_irq(&pgdat->lru_lock); } static void commit_charge(struct page *page, struct mem_cgroup *memcg, -- 1.8.3.1