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, USER_AGENT_SANE_1 autolearn=unavailable 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 771A6C33CAF for ; Wed, 22 Jan 2020 00:40:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 426532253D for ; Wed, 22 Jan 2020 00:40:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 426532253D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id D664A6B0007; Tue, 21 Jan 2020 19:40:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D17266B0008; Tue, 21 Jan 2020 19:40:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C08186B000C; Tue, 21 Jan 2020 19:40:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0140.hostedemail.com [216.40.44.140]) by kanga.kvack.org (Postfix) with ESMTP id AC4B76B0007 for ; Tue, 21 Jan 2020 19:40:57 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id 4B400180AD802 for ; Wed, 22 Jan 2020 00:40:57 +0000 (UTC) X-FDA: 76403415354.19.gate81_5f96ec105502c X-HE-Tag: gate81_5f96ec105502c X-Filterd-Recvd-Size: 3582 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Wed, 22 Jan 2020 00:40:56 +0000 (UTC) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Jan 2020 16:40:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,347,1574150400"; d="scan'208";a="425678924" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga005.fm.intel.com with ESMTP; 21 Jan 2020 16:40:53 -0800 Date: Wed, 22 Jan 2020 08:41:04 +0800 From: Wei Yang To: Yang Shi Cc: Wei Yang , akpm@linux-foundation.org, jhubbard@nvidia.com, vbabka@suse.cz, cl@linux.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mhocko@kernel.org Subject: Re: [Patch v2] mm/migrate.c: also overwrite error when it is bigger than zero Message-ID: <20200122004104.GC11409@richard> Reply-To: Wei Yang References: <20200119065753.21694-1-richardw.yang@linux.intel.com> <20200121015326.GE1567@richard> <6fc3e936-eed0-eb18-ecd8-36dcc4c51218@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6fc3e936-eed0-eb18-ecd8-36dcc4c51218@linux.alibaba.com> User-Agent: Mutt/1.9.4 (2018-02-28) 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: On Tue, Jan 21, 2020 at 11:30:03AM -0800, Yang Shi wrote: > > >On 1/20/20 5:53 PM, Wei Yang wrote: >> On Sun, Jan 19, 2020 at 02:57:53PM +0800, Wei Yang wrote: >> > If we get here after successfully adding page to list, err would be >> > 1 to indicate the page is queued in the list. >> > >> > Current code has two problems: >> > >> > * on success, 0 is not returned >> > * on error, if add_page_for_migratioin() return 1, and the following err1 >> > from do_move_pages_to_node() is set, the err1 is not returned since err >> > is 1 >> > >> > And these behaviors break the user interface. >> > >> > Fixes: e0153fc2c760 ("mm: move_pages: return valid node id in status if the >> > page is already on the target node"). >> > Signed-off-by: Wei Yang >> > >> > --- >> > v2: >> > * put more words to explain the error case >> > --- >> > mm/migrate.c | 2 +- >> > 1 file changed, 1 insertion(+), 1 deletion(-) >> > >> > diff --git a/mm/migrate.c b/mm/migrate.c >> > index 86873b6f38a7..430fdccc733e 100644 >> > --- a/mm/migrate.c >> > +++ b/mm/migrate.c >> > @@ -1676,7 +1676,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, >> > err1 = do_move_pages_to_node(mm, &pagelist, current_node); >> > if (!err1) >> > err1 = store_status(status, start, current_node, i - start); >> > - if (!err) >> > + if (err >= 0) >> > err = err1; >> Ok, as mentioned by Yang and Michal, only err == 0 means no error. > >I think Michal means do_move_pages_to_node() only, add_page_for_migration() >returns 1 on purpose. > >But, actually the syscall may still return > 0 value since err1 might be > 0. >Anyway, this is another regression. The patch itself looks correct to me. > >Acked-by: Yang Shi > Thanks > >> >> Sounds this regression should be fixed in another place. Let me send out >> another patch. >> >> > out: >> > return err; >> > -- >> > 2.17.1 -- Wei Yang Help you, Help me