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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EBB75C32771 for ; Wed, 21 Sep 2022 10:42:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 76E9D6B0072; Wed, 21 Sep 2022 06:42:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 71E396B0073; Wed, 21 Sep 2022 06:42:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 60CED940007; Wed, 21 Sep 2022 06:42:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 508E96B0072 for ; Wed, 21 Sep 2022 06:42:12 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 81B031404B4 for ; Wed, 21 Sep 2022 10:42:11 +0000 (UTC) X-FDA: 79935752862.08.8157A3E Received: from out30-57.freemail.mail.aliyun.com (out30-57.freemail.mail.aliyun.com [115.124.30.57]) by imf01.hostedemail.com (Postfix) with ESMTP id 087AA40017 for ; Wed, 21 Sep 2022 10:42:09 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R151e4;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=4;SR=0;TI=SMTPD_---0VQO.Rpi_1663756926; Received: from 30.97.48.63(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VQO.Rpi_1663756926) by smtp.aliyun-inc.com; Wed, 21 Sep 2022 18:42:06 +0800 Message-ID: <5b74c435-6dec-4346-e237-ad36bfcb9789@linux.alibaba.com> Date: Wed, 21 Sep 2022 18:42:24 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: Re: [PATCH v1] mm/vmscan: check the return value of migrate_pages() To: Li Zhong , linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: akpm@linux-foundation.org References: <20220917021257.3840548-1-floridsleeves@gmail.com> From: Baolin Wang In-Reply-To: <20220917021257.3840548-1-floridsleeves@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.57 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=alibaba.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663756931; a=rsa-sha256; cv=none; b=p5yLLsBs/CfJ2jeqG7crDkqi7WKGZ2ewru5B1IiHr9w2i0K5iJYe/HnGJa+yUf99aiRjlZ YDwtIsGB62igRpQ5ANoFnHggJ15S+1UZImEkdF/cyUAgvjMMmkH3rwMQ8yjQPGIOZYnLNr grlzsXIla/pXbmqm9HUiXjT5kARdAdg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663756931; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sxZuw8BqZ4iSvi6+eMWQiatD9WUqJMr7/6SO3F8lxvg=; b=sTUKdQpCouZIgjE4RAAOZoxWWurQHGStdbojqYEoc+m9Y97a92wKJC91FmmSvsuahh4Fyw hKtF5EH5BWp2IEY2+h0VXzzI4gpzAt0dA3f7SgG4ykCDgjHqHEPVfFGPzFEaP+FuRNLume AVBM+r3UlPyUyspOsOR2x7LBMJGjs6I= X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 087AA40017 X-Rspam-User: Authentication-Results: imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.57 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=alibaba.com X-Stat-Signature: d9n4t99f7ew5s9xfs1ifjcythd53rtas X-HE-Tag: 1663756929-129909 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: Hi, On 9/17/2022 10:12 AM, Li Zhong wrote: > Check the return value of migrate_pages() to check error exeuction. > > Signed-off-by: Li Zhong > --- > mm/vmscan.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index b2b1431352dc..50aaaa9377e2 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1547,6 +1547,7 @@ static unsigned int demote_page_list(struct list_head *demote_pages, > { > int target_nid = next_demotion_node(pgdat->node_id); > unsigned int nr_succeeded; > + int ret; > > if (list_empty(demote_pages)) > return 0; > @@ -1555,10 +1556,13 @@ static unsigned int demote_page_list(struct list_head *demote_pages, > return 0; > > /* Demotion ignores all cpuset and mempolicy settings */ > - migrate_pages(demote_pages, alloc_demote_page, NULL, > + ret = migrate_pages(demote_pages, alloc_demote_page, NULL, > target_nid, MIGRATE_ASYNC, MR_DEMOTION, > &nr_succeeded); > > + if (ret) > + putback_movable_pages(&pagelist); You can not just put them back into the original lru list, instead the caller has handled the failed-to-demote pages, which will try to reclaim them. In addition, the code cannot even be built successfully.