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=-13.0 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,URIBL_BLOCKED, 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 1B70EC433E0 for ; Tue, 4 Aug 2020 08:37:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1234A22B45 for ; Tue, 4 Aug 2020 08:37:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1234A22B45 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 8E3548D0131; Tue, 4 Aug 2020 04:37:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 86B748D0081; Tue, 4 Aug 2020 04:37:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 75E2E8D0131; Tue, 4 Aug 2020 04:37:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0183.hostedemail.com [216.40.44.183]) by kanga.kvack.org (Postfix) with ESMTP id 5CCD28D0081 for ; Tue, 4 Aug 2020 04:37:18 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 264491EE6 for ; Tue, 4 Aug 2020 08:37:18 +0000 (UTC) X-FDA: 77112231756.26.road00_3a044e226fa5 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id D27461804B655 for ; Tue, 4 Aug 2020 08:37:17 +0000 (UTC) X-HE-Tag: road00_3a044e226fa5 X-Filterd-Recvd-Size: 5019 Received: from out30-43.freemail.mail.aliyun.com (out30-43.freemail.mail.aliyun.com [115.124.30.43]) by imf38.hostedemail.com (Postfix) with ESMTP for ; Tue, 4 Aug 2020 08:37:16 +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=e01e01419;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=21;SR=0;TI=SMTPD_---0U4jIqSF_1596530228; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U4jIqSF_1596530228) by smtp.aliyun-inc.com(127.0.0.1); Tue, 04 Aug 2020 16:37:08 +0800 Subject: Re: [PATCH v17 00/21] per memcg 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, yang.shi@linux.alibaba.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, Vladimir Davydov , Michal Hocko References: <1595681998-19193-1-git-send-email-alex.shi@linux.alibaba.com> Message-ID: <7622d74e-5884-4ee5-382d-78d6476db18a@linux.alibaba.com> Date: Tue, 4 Aug 2020 16:36:51 +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: <1595681998-19193-1-git-send-email-alex.shi@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: D27461804B655 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: >From e2918c8fa741442255a2f12659f95dae94fdfe5d Mon Sep 17 00:00:00 2001 From: Alex Shi Date: Sat, 1 Aug 2020 22:49:31 +0800 Subject: [PATCH 3/3] mm/swap.c: optimizing __pagevec_lru_add lru_lock The current relock will unlock/lock lru_lock with every time lruvec changes, so it would cause frequency relock if 2 memcgs are reading file simultaneously. This patch will record the involved lru_lock and only hold them once in above scenario. That could reduce the lock contention. Using per cpu data intead of local stack data to avoid repeatly INIT_LIST_HEAD action. [lkp@intel.com: found a build issue in the original patch, thanks] 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 | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 51 insertions(+), 6 deletions(-) diff --git a/mm/swap.c b/mm/swap.c index d88a6c650a7c..e227fec6983c 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -72,6 +72,27 @@ static DEFINE_PER_CPU(struct lru_pvecs, lru_pvecs) = { .lock = INIT_LOCAL_LOCK(lock), }; +struct pvlvs { + struct list_head lists[PAGEVEC_SIZE]; + struct lruvec *vecs[PAGEVEC_SIZE]; +}; +static DEFINE_PER_CPU(struct pvlvs, pvlvs); + +static int __init pvlvs_init(void) { + int i, cpu; + struct pvlvs *pvecs; + + for (cpu = 0; cpu < NR_CPUS; cpu++) { + if (!cpu_possible(cpu)) + continue; + pvecs = per_cpu_ptr(&pvlvs, cpu); + for (i = 0; i < PAGEVEC_SIZE; i++) + INIT_LIST_HEAD(&pvecs->lists[i]); + } + return 0; +} +subsys_initcall(pvlvs_init); + /* * This path almost never happens for VM activity - pages are normally * freed via pagevecs. But it gets used by networking. @@ -963,18 +984,42 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec) */ void __pagevec_lru_add(struct pagevec *pvec) { - int i; + int i, j, total = 0; struct lruvec *lruvec = NULL; unsigned long flags = 0; + struct page *page; + struct pvlvs *lvs = this_cpu_ptr(&pvlvs); + /* Sort the same lruvec pages on a list. */ for (i = 0; i < pagevec_count(pvec); i++) { - struct page *page = pvec->pages[i]; + page = pvec->pages[i]; + lruvec = mem_cgroup_page_lruvec(page, page_pgdat(page)); + + /* Try to find a same lruvec */ + for (j = 0; j <= total; j++) + if (lruvec == lvs->vecs[j]) + break; + /* A new lruvec */ + if (j > total) { + lvs->vecs[total] = lruvec; + j = total; + total++; + } - lruvec = relock_page_lruvec_irqsave(page, lruvec, &flags); - __pagevec_lru_add_fn(page, lruvec); + list_add(&page->lru, &lvs->lists[j]); } - if (lruvec) - unlock_page_lruvec_irqrestore(lruvec, flags); + + for (i = 0; i < total; i++) { + spin_lock_irqsave(&lvs->vecs[i]->lru_lock, flags); + while (!list_empty(&lvs->lists[i])) { + page = lru_to_page(&lvs->lists[i]); + list_del(&page->lru); + __pagevec_lru_add_fn(page, lvs->vecs[i]); + } + spin_unlock_irqrestore(&lvs->vecs[i]->lru_lock, flags); + lvs->vecs[i] = NULL; + } + release_pages(pvec->pages, pvec->nr); pagevec_reinit(pvec); } -- 1.8.3.1