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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C38DBEB64DC for ; Wed, 21 Jun 2023 09:12:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230226AbjFUJMk (ORCPT ); Wed, 21 Jun 2023 05:12:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231283AbjFUJLh (ORCPT ); Wed, 21 Jun 2023 05:11:37 -0400 Received: from out30-111.freemail.mail.aliyun.com (out30-111.freemail.mail.aliyun.com [115.124.30.111]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6943E19B4 for ; Wed, 21 Jun 2023 02:10:58 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R821e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0VlfKbH7_1687338654; Received: from 30.97.48.59(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VlfKbH7_1687338654) by smtp.aliyun-inc.com; Wed, 21 Jun 2023 17:10:55 +0800 Message-ID: <58d0d829-da04-0f77-eedf-8bfa519b52f0@linux.alibaba.com> Date: Wed, 21 Jun 2023 17:11:15 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.11.2 Subject: Re: [PATCH -next v2 1/2] mm: compaction: convert to use a folio in isolate_migratepages_block() To: Kefeng Wang , akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, willy@infradead.org, jgowans@amazon.com, yuzhao@google.com References: <20230619110718.65679-1-wangkefeng.wang@huawei.com> From: Baolin Wang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/21/2023 4:36 PM, Kefeng Wang wrote: > > > On 2023/6/21 14:20, Baolin Wang wrote: >> Hi >> >> On 6/19/2023 7:07 PM, Kefeng Wang wrote: >>> Directly use a folio instead of page_folio() when page successfully >>> isolated (hugepage and movable page) and after folio_get_nontail_page(), >>> which removes several calls to compound_head(). >>> >>> Signed-off-by: Kefeng Wang >>> --- >>> v2: >>> - update comments and use node_stat_mod_folio, per Matthew Wilcox >>> - add missed PageLRU conversion and rebase on next-20230619 >>> >>>   mm/compaction.c | 84 ++++++++++++++++++++++++++----------------------- >>>   1 file changed, 44 insertions(+), 40 deletions(-) >>> >>> diff --git a/mm/compaction.c b/mm/compaction.c >>> index 6149a2d324be..0334eefe4bfa 100644 >>> --- a/mm/compaction.c >>> +++ b/mm/compaction.c >>> @@ -795,6 +795,7 @@ isolate_migratepages_block(struct compact_control >>> *cc, unsigned long low_pfn, >>>       struct lruvec *lruvec; >>>       unsigned long flags = 0; >>>       struct lruvec *locked = NULL; >>> +    struct folio *folio = NULL; >>>       struct page *page = NULL, *valid_page = NULL; >>>       struct address_space *mapping; >>>       unsigned long start_pfn = low_pfn; >>> @@ -891,7 +892,7 @@ isolate_migratepages_block(struct compact_control >>> *cc, unsigned long low_pfn, >>>           if (!valid_page && pageblock_aligned(low_pfn)) { >>>               if (!isolation_suitable(cc, page)) { >>>                   low_pfn = end_pfn; >>> -                page = NULL; >>> +                folio = NULL; >>>                   goto isolate_abort; >>>               } >>>               valid_page = page; >>> @@ -923,7 +924,8 @@ isolate_migratepages_block(struct compact_control >>> *cc, unsigned long low_pfn, >>>                    * Hugepage was successfully isolated and placed >>>                    * on the cc->migratepages list. >>>                    */ >>> -                low_pfn += compound_nr(page) - 1; >>> +                folio = page_folio(page); >>> +                low_pfn += folio_nr_pages(folio) - 1; >>>                   goto isolate_success_no_list; >>>               } >>> @@ -991,8 +993,10 @@ isolate_migratepages_block(struct >>> compact_control *cc, unsigned long low_pfn, >>>                       locked = NULL; >>>                   } >>> -                if (isolate_movable_page(page, mode)) >>> +                if (isolate_movable_page(page, mode)) { >>> +                    folio = page_folio(page); >>>                       goto isolate_success; >>> +                } >>>               } >>>               goto isolate_fail; >>> @@ -1003,7 +1007,8 @@ isolate_migratepages_block(struct >>> compact_control *cc, unsigned long low_pfn, >>>            * sure the page is not being freed elsewhere -- the >>>            * page release code relies on it. >>>            */ >>> -        if (unlikely(!get_page_unless_zero(page))) >>> +        folio = folio_get_nontail_page(page); >> >> I'm just curious, how can you make sure the 'page' is not a tail page? >> Since the validation is lockless. > > folio_get_nontail_page is added by commit "3c1ea2c729ef (mm: add > folio_get_nontail_page())", see more comments [1] > > [1] https://lore.kernel.org/lkml/Y86sRiKAAOz2myNe@casper.infradead.org/ I see. Thanks for sharing. The changes look good to me at least. Please feel free to add: Reviewed-by: Baolin Wang