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=-2.2 required=3.0 tests=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 634AEC3F68F for ; Mon, 13 Jan 2020 08:23:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 327BA207E0 for ; Mon, 13 Jan 2020 08:23:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 327BA207E0 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 C05F28E0006; Mon, 13 Jan 2020 03:23:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BB6DE8E0001; Mon, 13 Jan 2020 03:23:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ACCEF8E0006; Mon, 13 Jan 2020 03:23:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0173.hostedemail.com [216.40.44.173]) by kanga.kvack.org (Postfix) with ESMTP id 952428E0001 for ; Mon, 13 Jan 2020 03:23:19 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 43CE8181AC9B6 for ; Mon, 13 Jan 2020 08:23:19 +0000 (UTC) X-FDA: 76371921318.12.toys74_7433c1e94e734 X-HE-Tag: toys74_7433c1e94e734 X-Filterd-Recvd-Size: 2325 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Mon, 13 Jan 2020 08:23:18 +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 fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Jan 2020 00:23:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,428,1571727600"; d="scan'208";a="422737910" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga005.fm.intel.com with ESMTP; 13 Jan 2020 00:23:15 -0800 Date: Mon, 13 Jan 2020 16:23:08 +0800 From: Wei Yang To: "Kirill A. Shutemov" Cc: Wei Yang , hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com, akpm@linux-foundation.org, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kirill.shutemov@linux.intel.com, yang.shi@linux.alibaba.com, alexander.duyck@gmail.com, rientjes@google.com Subject: Re: [Patch v2] mm: thp: grab the lock before manipulation defer list Message-ID: <20200113082308.GB27972@richard> Reply-To: Wei Yang References: <20200109143054.13203-1-richardw.yang@linux.intel.com> <20200111000352.efy6krudecpshezh@box> <20200112022858.GA17733@richard> <20200112225718.5vqzezfclacujyx3@box> <20200113004457.GA27762@richard> <20200113073614.jo2txcmazwlesl7b@box.shutemov.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200113073614.jo2txcmazwlesl7b@box.shutemov.name> 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 Mon, Jan 13, 2020 at 10:36:14AM +0300, Kirill A. Shutemov wrote: >On Mon, Jan 13, 2020 at 08:44:57AM +0800, Wei Yang wrote: >> >> It is possible two page in the same pgdate or memcg grab page lock >> >> respectively and then access the same defer queue concurrently. >> >> If my understanding is correct, you agree with my statement? > >Which one? If the one above then no. list_empty only accesses list_head >for the struct page, not the queue. > Ah, I get your point. >-- > Kirill A. Shutemov -- Wei Yang Help you, Help me