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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,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 71EECC35240 for ; Thu, 23 Jan 2020 23:37:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 46CEE20718 for ; Thu, 23 Jan 2020 23:37:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729347AbgAWXhP (ORCPT ); Thu, 23 Jan 2020 18:37:15 -0500 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:32933 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729288AbgAWXhP (ORCPT ); Thu, 23 Jan 2020 18:37:15 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04396;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0ToQ2aA1_1579822620; Received: from US-143344MP.local(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0ToQ2aA1_1579822620) by smtp.aliyun-inc.com(127.0.0.1); Fri, 24 Jan 2020 07:37:12 +0800 Subject: Re: [v2 PATCH] mm: move_pages: report the number of non-attempted pages To: Wei Yang Cc: mhocko@suse.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <1579736331-85494-1-git-send-email-yang.shi@linux.alibaba.com> <20200123225940.GC29851@richard> From: Yang Shi Message-ID: <424a0fbb-1e9a-ca9d-ba43-cb247d7a4b67@linux.alibaba.com> Date: Thu, 23 Jan 2020 15:36:58 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20200123225940.GC29851@richard> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On 1/23/20 2:59 PM, Wei Yang wrote: > On Thu, Jan 23, 2020 at 07:38:51AM +0800, Yang Shi wrote: >> Since commit a49bd4d71637 ("mm, numa: rework do_pages_move"), >> the semantic of move_pages() was changed to return the number of >> non-migrated pages (failed to migration) and the call would be aborted >> immediately if migrate_pages() returns positive value. But it didn't >> report the number of pages that we even haven't attempted to migrate. >> So, fix it by including non-attempted pages in the return value. >> >> Fixes: a49bd4d71637 ("mm, numa: rework do_pages_move") >> Suggested-by: Michal Hocko >> Cc: Wei Yang >> Cc: [4.17+] >> Signed-off-by: Yang Shi >> --- >> v2: Rebased on top of the latest mainline kernel per Andrew >> >> mm/migrate.c | 24 ++++++++++++++++++++++-- >> 1 file changed, 22 insertions(+), 2 deletions(-) >> >> diff --git a/mm/migrate.c b/mm/migrate.c >> index 86873b6..9b8eb5d 100644 >> --- a/mm/migrate.c >> +++ b/mm/migrate.c >> @@ -1627,8 +1627,18 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, >> start = i; >> } else if (node != current_node) { >> err = do_move_pages_to_node(mm, &pagelist, current_node); >> - if (err) >> + if (err) { >> + /* >> + * Positive err means the number of failed >> + * pages to migrate. Since we are going to >> + * abort and return the number of non-migrated >> + * pages, so need incude the rest of the >> + * nr_pages that have not attempted as well. >> + */ >> + if (err > 0) >> + err += nr_pages - i - 1; >> goto out; >> + } >> err = store_status(status, start, current_node, i - start); >> if (err) >> goto out; >> @@ -1659,8 +1669,11 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, >> goto out_flush; >> >> err = do_move_pages_to_node(mm, &pagelist, current_node); >> - if (err) >> + if (err) { >> + if (err > 0) >> + err += nr_pages - i - 1; >> goto out; >> + } >> if (i > start) { >> err = store_status(status, start, current_node, i - start); >> if (err) >> @@ -1674,6 +1687,13 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, >> >> /* Make sure we do not overwrite the existing error */ >> err1 = do_move_pages_to_node(mm, &pagelist, current_node); >> + /* >> + * Don't have to report non-attempted pages here since: > In previous comment, you use "non-migrated". Here is "non-attempted". What's > the difference? In that comment "non-migrated" includes both reported by migrate_pages() and the non-attempted. > >> + * - If the above loop is done gracefully there is not non-attempted >> + * page. >> + * - If the above loop is aborted to it means more fatal error >> + * happened, should return err. >> + */ >> if (!err1) >> err1 = store_status(status, start, current_node, i - start); >> if (!err) >> -- >> 1.8.3.1