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=-13.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 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 A14A6C433E1 for ; Wed, 26 Aug 2020 09:09:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6B40620786 for ; Wed, 26 Aug 2020 09:09:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6B40620786 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 08C016B0006; Wed, 26 Aug 2020 05:09:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 014936B0007; Wed, 26 Aug 2020 05:09:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E21AC6B0008; Wed, 26 Aug 2020 05:09:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0129.hostedemail.com [216.40.44.129]) by kanga.kvack.org (Postfix) with ESMTP id C76646B0006 for ; Wed, 26 Aug 2020 05:09:31 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 7F02E181AC217 for ; Wed, 26 Aug 2020 09:09:31 +0000 (UTC) X-FDA: 77192146542.28.face62_010a9c927063 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id 514B6A743 for ; Wed, 26 Aug 2020 09:09:31 +0000 (UTC) X-HE-Tag: face62_010a9c927063 X-Filterd-Recvd-Size: 4536 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by imf49.hostedemail.com (Postfix) with ESMTP for ; Wed, 26 Aug 2020 09:09:30 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01358;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=21;SR=0;TI=SMTPD_---0U6v-68g_1598432963; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U6v-68g_1598432963) by smtp.aliyun-inc.com(127.0.0.1); Wed, 26 Aug 2020 17:09:24 +0800 Subject: Re: [PATCH v18 27/32] mm/swap.c: optimizing __pagevec_lru_add lru_lock 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 References: <1598273705-69124-1-git-send-email-alex.shi@linux.alibaba.com> <1598273705-69124-28-git-send-email-alex.shi@linux.alibaba.com> Message-ID: <57cea811-13bd-c026-01dc-69bd9eafa014@linux.alibaba.com> Date: Wed, 26 Aug 2020 17:07:53 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <1598273705-69124-28-git-send-email-alex.shi@linux.alibaba.com> Content-Type: text/plain; charset=gbk Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 514B6A743 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: The patch need update since a bug found. >From 547d95205e666c7c5a81c44b7b1f8e1b6c7b1749 Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Sat, 1 Aug 2020 22:49:31 +0800 Subject: [PATCH] mm/swap.c: optimizing __pagevec_lru_add lru_lock The current relock logical will change lru_lock when if found a new lruvec, so if 2 memcgs are reading file or alloc page equally, they could hold the lru_lock alternately. This patch will record the needed lru_lock and only hold them once in above scenario. That could reduce the lock contention. Suggested-by: Konstantin Khlebnikov Signed-off-by: Alex Shi Cc: Andrew Morton Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/swap.c | 42 +++++++++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 7 deletions(-) diff --git a/mm/swap.c b/mm/swap.c index 2ac78e8fab71..dba3f0aba2a0 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -958,24 +958,52 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec) trace_mm_lru_insertion(page, lru); } +struct add_lruvecs { + struct list_head lists[PAGEVEC_SIZE]; + struct lruvec *vecs[PAGEVEC_SIZE]; +}; + /* * Add the passed pages to the LRU, then drop the caller's refcount * on them. Reinitialises the caller's pagevec. */ void __pagevec_lru_add(struct pagevec *pvec) { - int i; + int i, j, total; struct lruvec *lruvec = NULL; unsigned long flags = 0; + struct page *page; + struct add_lruvecs lruvecs; + + for (i = total = 0; i < pagevec_count(pvec); i++) { + page = pvec->pages[i]; + lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page)); + lruvecs.vecs[i] = NULL; + + /* Try to find a same lruvec */ + for (j = 0; j < total; j++) + if (lruvec == lruvecs.vecs[j]) + break; + /* A new lruvec */ + if (j == total) { + INIT_LIST_HEAD(&lruvecs.lists[total]); + lruvecs.vecs[total] = lruvec; + total++; + } - for (i = 0; i < pagevec_count(pvec); i++) { - struct page *page = pvec->pages[i]; + list_add(&page->lru, &lruvecs.lists[j]); + } - lruvec = relock_page_lruvec_irqsave(page, lruvec, &flags); - __pagevec_lru_add_fn(page, lruvec); + for (i = 0; i < total; i++) { + spin_lock_irqsave(&lruvecs.vecs[i]->lru_lock, flags); + while (!list_empty(&lruvecs.lists[i])) { + page = lru_to_page(&lruvecs.lists[i]); + list_del(&page->lru); + __pagevec_lru_add_fn(page, lruvecs.vecs[i]); + } + spin_unlock_irqrestore(&lruvecs.vecs[i]->lru_lock, flags); } - if (lruvec) - unlock_page_lruvec_irqrestore(lruvec, flags); + release_pages(pvec->pages, pvec->nr); pagevec_reinit(pvec); } -- 1.8.3.1