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=-11.5 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,URIBL_BLOCKED, USER_AGENT_SANE_1 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 6BD64C433DF for ; Thu, 6 Aug 2020 03:48:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DB8D2086A for ; Thu, 6 Aug 2020 03:48:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728031AbgHFDsU (ORCPT ); Wed, 5 Aug 2020 23:48:20 -0400 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:33989 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726026AbgHFDsT (ORCPT ); Wed, 5 Aug 2020 23:48:19 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;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=19;SR=0;TI=SMTPD_---0U4tH-Rl_1596685693; Received: from IT-FVFX43SYHV2H.local(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0U4tH-Rl_1596685693) by smtp.aliyun-inc.com(127.0.0.1); Thu, 06 Aug 2020 11:48:14 +0800 Subject: Re: [PATCH v17 01/21] mm/vmscan: remove unnecessary lruvec adding 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 References: <1595681998-19193-1-git-send-email-alex.shi@linux.alibaba.com> <1595681998-19193-2-git-send-email-alex.shi@linux.alibaba.com> Message-ID: Date: Thu, 6 Aug 2020 11:47:53 +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: <1595681998-19193-2-git-send-email-alex.shi@linux.alibaba.com> Content-Type: text/plain; charset=gbk Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ÔÚ 2020/7/25 ÏÂÎç8:59, Alex Shi дµÀ: > We don't have to add a freeable page into lru and then remove from it. > This change saves a couple of actions and makes the moving more clear. > > The SetPageLRU needs to be kept here for list intergrity. > Otherwise: > #0 mave_pages_to_lru #1 release_pages > if (put_page_testzero()) > if !put_page_testzero > !PageLRU //skip lru_lock > list_add(&page->lru,) > list_add(&page->lru,) //corrupt The race comments should be corrected to this: /* * The SetPageLRU needs to be kept here for list intergrity. * Otherwise: * #0 mave_pages_to_lru #1 release_pages * if !put_page_testzero * if (put_page_testzero()) * !PageLRU //skip lru_lock * SetPageLRU() * list_add(&page->lru,) * list_add(&page->lru,) */ > > [akpm@linux-foundation.org: coding style fixes] > Signed-off-by: Alex Shi > Cc: Andrew Morton > Cc: Johannes Weiner > Cc: Tejun Heo > Cc: Matthew Wilcox > Cc: Hugh Dickins > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > mm/vmscan.c | 37 ++++++++++++++++++++++++------------- > 1 file changed, 24 insertions(+), 13 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 749d239c62b2..ddb29d813d77 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1856,26 +1856,29 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > while (!list_empty(list)) { > page = lru_to_page(list); > VM_BUG_ON_PAGE(PageLRU(page), page); > + list_del(&page->lru); > if (unlikely(!page_evictable(page))) { > - list_del(&page->lru); > spin_unlock_irq(&pgdat->lru_lock); > putback_lru_page(page); > spin_lock_irq(&pgdat->lru_lock); > continue; > } > - lruvec = mem_cgroup_page_lruvec(page, pgdat); > > + /* > + * The SetPageLRU needs to be kept here for list intergrity. > + * Otherwise: > + * #0 mave_pages_to_lru #1 release_pages > + * if (put_page_testzero()) > + * if !put_page_testzero > + * !PageLRU //skip lru_lock > + * list_add(&page->lru,) > + * list_add(&page->lru,) //corrupt > + */ /* * The SetPageLRU needs to be kept here for list intergrity. * Otherwise: * #0 mave_pages_to_lru #1 release_pages * if !put_page_testzero * if (put_page_testzero()) * !PageLRU //skip lru_lock * SetPageLRU() * list_add(&page->lru,) * list_add(&page->lru,) */ > SetPageLRU(page); > - lru = page_lru(page); > > - nr_pages = hpage_nr_pages(page); > - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); > - list_move(&page->lru, &lruvec->lists[lru]); > - > - if (put_page_testzero(page)) { > + if (unlikely(put_page_testzero(page))) { > __ClearPageLRU(page); > __ClearPageActive(page); > - del_page_from_lru_list(page, lruvec, lru); > > if (unlikely(PageCompound(page))) { > spin_unlock_irq(&pgdat->lru_lock); > @@ -1883,11 +1886,19 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec, > spin_lock_irq(&pgdat->lru_lock); > } else > list_add(&page->lru, &pages_to_free); > - } else { > - nr_moved += nr_pages; > - if (PageActive(page)) > - workingset_age_nonresident(lruvec, nr_pages); > + > + continue; > } > + > + lruvec = mem_cgroup_page_lruvec(page, pgdat); > + lru = page_lru(page); > + nr_pages = hpage_nr_pages(page); > + > + update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); > + list_add(&page->lru, &lruvec->lists[lru]); > + nr_moved += nr_pages; > + if (PageActive(page)) > + workingset_age_nonresident(lruvec, nr_pages); > } > > /* > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Shi Subject: Re: [PATCH v17 01/21] mm/vmscan: remove unnecessary lruvec adding Date: Thu, 6 Aug 2020 11:47:53 +0800 Message-ID: References: <1595681998-19193-1-git-send-email-alex.shi@linux.alibaba.com> <1595681998-19193-2-git-send-email-alex.shi@linux.alibaba.com> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1595681998-19193-2-git-send-email-alex.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="iso-8859-1" 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 =D4=DA 2020/7/25 =CF=C2=CE=E78:59, Alex Shi =D0=B4=B5=C0: > We don't have to add a freeable page into lru and then remove from it. > This change saves a couple of actions and makes the moving more clear. >=20 > The SetPageLRU needs to be kept here for list intergrity. > Otherwise: > #0 mave_pages_to_lru #1 release_pages > if (put_page_testzero()) > if !put_page_testzero > !PageLRU //skip lru_lock > list_add(&page->lru,) > list_add(&page->lru,) //corrupt The race comments should be corrected to this: /* * The SetPageLRU needs to be kept here for list intergrity. * Otherwise: * #0 mave_pages_to_lru #1 release_pages * if !put_page_testzero * if (put_page_testzero= ()) * !PageLRU //skip lru= _lock * SetPageLRU() * list_add(&page->lru,) * list_add(&page->l= ru,) */ >=20 > [akpm@linux-foundation.org: coding style fixes] > Signed-off-by: Alex Shi > Cc: Andrew Morton > Cc: Johannes Weiner > Cc: Tejun Heo > Cc: Matthew Wilcox > Cc: Hugh Dickins > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > mm/vmscan.c | 37 ++++++++++++++++++++++++------------- > 1 file changed, 24 insertions(+), 13 deletions(-) >=20 > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 749d239c62b2..ddb29d813d77 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1856,26 +1856,29 @@ static unsigned noinline_for_stack move_pages_to_= lru(struct lruvec *lruvec, > while (!list_empty(list)) { > page =3D lru_to_page(list); > VM_BUG_ON_PAGE(PageLRU(page), page); > + list_del(&page->lru); > if (unlikely(!page_evictable(page))) { > - list_del(&page->lru); > spin_unlock_irq(&pgdat->lru_lock); > putback_lru_page(page); > spin_lock_irq(&pgdat->lru_lock); > continue; > } > - lruvec =3D mem_cgroup_page_lruvec(page, pgdat); > =20 > + /* > + * The SetPageLRU needs to be kept here for list intergrity. > + * Otherwise: > + * #0 mave_pages_to_lru #1 release_pages > + * if (put_page_testzero()) > + * if !put_page_testzero > + * !PageLRU //skip lru_lock > + * list_add(&page->lru,) > + * list_add(&page->lru,) //corrupt > + */ /* * The SetPageLRU needs to be kept here for list intergrity. * Otherwise: * #0 mave_pages_to_lru #1 release_pages * if !put_page_testzero * if (put_page_testzero= ()) * !PageLRU //skip lru= _lock * SetPageLRU() * list_add(&page->lru,) * list_add(&page->l= ru,) */ > SetPageLRU(page); > - lru =3D page_lru(page); > =20 > - nr_pages =3D hpage_nr_pages(page); > - update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); > - list_move(&page->lru, &lruvec->lists[lru]); > - > - if (put_page_testzero(page)) { > + if (unlikely(put_page_testzero(page))) { > __ClearPageLRU(page); > __ClearPageActive(page); > - del_page_from_lru_list(page, lruvec, lru); > =20 > if (unlikely(PageCompound(page))) { > spin_unlock_irq(&pgdat->lru_lock); > @@ -1883,11 +1886,19 @@ static unsigned noinline_for_stack move_pages_to_= lru(struct lruvec *lruvec, > spin_lock_irq(&pgdat->lru_lock); > } else > list_add(&page->lru, &pages_to_free); > - } else { > - nr_moved +=3D nr_pages; > - if (PageActive(page)) > - workingset_age_nonresident(lruvec, nr_pages); > + > + continue; > } > + > + lruvec =3D mem_cgroup_page_lruvec(page, pgdat); > + lru =3D page_lru(page); > + nr_pages =3D hpage_nr_pages(page); > + > + update_lru_size(lruvec, lru, page_zonenum(page), nr_pages); > + list_add(&page->lru, &lruvec->lists[lru]); > + nr_moved +=3D nr_pages; > + if (PageActive(page)) > + workingset_age_nonresident(lruvec, nr_pages); > } > =20 > /* >=20