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 86677CCA473 for ; Fri, 24 Jun 2022 09:51:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229669AbiFXJvZ (ORCPT ); Fri, 24 Jun 2022 05:51:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229469AbiFXJvY (ORCPT ); Fri, 24 Jun 2022 05:51:24 -0400 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 938FE794CA for ; Fri, 24 Jun 2022 02:51:22 -0700 (PDT) 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=ay29a033018046059;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0VHGqj-b_1656064279; Received: from 30.97.49.29(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VHGqj-b_1656064279) by smtp.aliyun-inc.com; Fri, 24 Jun 2022 17:51:19 +0800 Message-ID: Date: Fri, 24 Jun 2022 17:51:25 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH 5/7] migrate_pages(): fix failure counting for THP on -ENOSYS To: Huang Ying , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Zi Yan , Yang Shi References: <20220624025309.1033400-1-ying.huang@intel.com> <20220624025309.1033400-6-ying.huang@intel.com> From: Baolin Wang In-Reply-To: <20220624025309.1033400-6-ying.huang@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/24/2022 10:53 AM, Huang Ying wrote: > If THP or hugetlbfs page migration isn't supported, unmap_and_move() > or unmap_and_move_huge_page() will return -ENOSYS. For THP, splitting > will be tried, but if splitting doesn't succeed, the THP will be left > in "from" list wrongly. If some other pages are retried, the THP > migration failure will counted again. This is fixed via moving the > failure THP from "from" to "ret_pages". > > Another issue of the original code is that the unsupported failure > processing isn't consistent between THP and hugetlbfs page. Make them > consistent in this patch to make the code easier to be understood too. > > Signed-off-by: "Huang, Ying" > Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") > Cc: Baolin Wang > Cc: Zi Yan > Cc: Yang Shi > --- LGTM. Reviewed-by: Baolin Wang > mm/migrate.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 61dab3025a1d..9d1883d5927f 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1191,10 +1191,8 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, > * tables or check whether the hugepage is pmd-based or not before > * kicking migration. > */ > - if (!hugepage_migration_supported(page_hstate(hpage))) { > - list_move_tail(&hpage->lru, ret); > + if (!hugepage_migration_supported(page_hstate(hpage))) > return -ENOSYS; > - } > > if (page_count(hpage) == 1) { > /* page was freed from under us. So we are done. */ > @@ -1391,6 +1389,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > * page will be put back > * -EAGAIN: stay on the from list > * -ENOMEM: stay on the from list > + * -ENOSYS: stay on the from list > * Other errno: put on ret_pages list then splice to > * from list > */ > @@ -1420,6 +1419,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > } > > nr_failed_pages += nr_subpages; > + list_move_tail(&page->lru, &ret_pages); > break; > case -ENOMEM: > /*