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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 89C40C43461 for ; Tue, 8 Sep 2020 08:52:03 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 43A1B2166E for ; Tue, 8 Sep 2020 08:52:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 43A1B2166E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 947086B0002; Tue, 8 Sep 2020 04:52:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8F9E16B0037; Tue, 8 Sep 2020 04:52:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 80D936B0055; Tue, 8 Sep 2020 04:52:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0245.hostedemail.com [216.40.44.245]) by kanga.kvack.org (Postfix) with ESMTP id 6B1CA6B0002 for ; Tue, 8 Sep 2020 04:52:02 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 30AC4180AD801 for ; Tue, 8 Sep 2020 08:52:02 +0000 (UTC) X-FDA: 77239276884.04.skin36_2517c0c270d3 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id 0A3AD800C888 for ; Tue, 8 Sep 2020 08:52:02 +0000 (UTC) X-HE-Tag: skin36_2517c0c270d3 X-Filterd-Recvd-Size: 2226 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf16.hostedemail.com (Postfix) with ESMTP for ; Tue, 8 Sep 2020 08:52:01 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 3551BACA3; Tue, 8 Sep 2020 08:52:01 +0000 (UTC) Date: Tue, 8 Sep 2020 10:51:57 +0200 From: Oscar Salvador To: HORIGUCHI =?utf-8?B?TkFPWUEo5aCA5Y+j44CA55u05LmfKQ==?= Cc: "yaoaili126@163.com" , "linux-mm@kvack.org" , "YANGFENG1@kingsoft.com" , Aili Yao , "willy@infradead.org" Subject: Re: [PATCH] Fix incorrect compound page flags store Message-ID: <20200908085153.GA12690@linux> References: <20200908034441.16359-1-yaoaili126@163.com> <20200908070210.GA14393@hori.linux.bs1.fc.nec.co.jp> <20200908072603.GA11245@linux> <20200908083630.GA15481@hori.linux.bs1.fc.nec.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200908083630.GA15481@hori.linux.bs1.fc.nec.co.jp> User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: 0A3AD800C888 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.004547, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Sep 08, 2020 at 08:36:32AM +0000, HORIGUCHI NAOYA(=E5=A0=80=E5=8F= =A3 =E7=9B=B4=E4=B9=9F) wrote: >=20 > Theoretically, it could happen that a error could be collapsed into a n= ew I guess you meant page here? ^^^^ > thp just after passing over the following block: >=20 > 1408 if (PageTransHuge(hpage)) { > 1409 if (try_to_split_thp_page(p, "Memory Failure") = < 0) { > 1410 action_result(pfn, MF_MSG_UNSPLIT_THP, = MF_IGNORED); > 1411 return -EBUSY; > 1412 } > 1413 VM_BUG_ON_PAGE(!page_count(p), p); > 1414 } >=20 > So I feel that some check might be added after holding page lock to avo= id > that case. Or acutally, it might better that moving the above block int= o > page lock is more better for simpler code. I will have a look at this. Thanks --=20 Oscar Salvador SUSE L3