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, URIBL_BLOCKED,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 64E51C32771 for ; Tue, 21 Jan 2020 01:53:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2486C2073A for ; Tue, 21 Jan 2020 01:53:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2486C2073A 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 C108F6B0003; Mon, 20 Jan 2020 20:53:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BC1F36B0005; Mon, 20 Jan 2020 20:53:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AD81F6B0006; Mon, 20 Jan 2020 20:53:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0160.hostedemail.com [216.40.44.160]) by kanga.kvack.org (Postfix) with ESMTP id 9BFD26B0003 for ; Mon, 20 Jan 2020 20:53:19 -0500 (EST) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 433FB2DFA for ; Tue, 21 Jan 2020 01:53:19 +0000 (UTC) X-FDA: 76399968918.14.north78_57233a56cf000 X-HE-Tag: north78_57233a56cf000 X-Filterd-Recvd-Size: 2877 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by imf07.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Jan 2020 01:53:18 +0000 (UTC) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Jan 2020 17:53:16 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,344,1574150400"; d="scan'208";a="220797769" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga007.fm.intel.com with ESMTP; 20 Jan 2020 17:53:15 -0800 Date: Tue, 21 Jan 2020 09:53:26 +0800 From: Wei Yang To: Wei Yang Cc: akpm@linux-foundation.org, yang.shi@linux.alibaba.com, 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: <20200121015326.GE1567@richard> Reply-To: Wei Yang References: <20200119065753.21694-1-richardw.yang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200119065753.21694-1-richardw.yang@linux.intel.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 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. 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