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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 0858CC433DF for ; Mon, 12 Oct 2020 13:54:41 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4B4522074F for ; Mon, 12 Oct 2020 13:54:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B4522074F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 958D9940007; Mon, 12 Oct 2020 09:54:39 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 90920900002; Mon, 12 Oct 2020 09:54:39 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7CFC9940007; Mon, 12 Oct 2020 09:54:39 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0084.hostedemail.com [216.40.44.84]) by kanga.kvack.org (Postfix) with ESMTP id 4F2DF900002 for ; Mon, 12 Oct 2020 09:54:39 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id A210A181AE863 for ; Mon, 12 Oct 2020 13:54:38 +0000 (UTC) X-FDA: 77363418636.26.spade54_2d04c98271fb Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id 7D2511804B640 for ; Mon, 12 Oct 2020 13:54:38 +0000 (UTC) X-HE-Tag: spade54_2d04c98271fb X-Filterd-Recvd-Size: 2203 Received: from huawei.com (szxga08-in.huawei.com [45.249.212.255]) by imf50.hostedemail.com (Postfix) with ESMTP for ; Mon, 12 Oct 2020 13:54:37 +0000 (UTC) Received: from dggeme752-chm.china.huawei.com (unknown [172.30.72.56]) by Forcepoint Email with ESMTP id D8E24734CB159E6780CF; Mon, 12 Oct 2020 21:54:29 +0800 (CST) Received: from dggeme753-chm.china.huawei.com (10.3.19.99) by dggeme752-chm.china.huawei.com (10.3.19.98) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1913.5; Mon, 12 Oct 2020 21:54:29 +0800 Received: from dggeme753-chm.china.huawei.com ([10.7.64.70]) by dggeme753-chm.china.huawei.com ([10.7.64.70]) with mapi id 15.01.1913.007; Mon, 12 Oct 2020 21:54:29 +0800 From: linmiaohe To: "vitalywool@gmail.com" CC: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: [Question] About z3fold page migration Thread-Topic: [Question] About z3fold page migration Thread-Index: AdagnzMIx4Seyi2qROGt7qSVacTSPg== Date: Mon, 12 Oct 2020 13:54:29 +0000 Message-ID: <1f19b35baad347f08d02b90239214196@huawei.com> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.174.179.54] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-CFilter-Loop: Reflected 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 Vitaly: Many thanks for your brilliant z3fold code. I am reading it and have some = questions about it. It's very nice of you if you can explain it for me. 1.page->private is used in z3fold but PagePrivate flag is never set, shoul= d we SetPagePrivate for it? 2.Since PagePrivate flag is never set, why we ClearPagePrivate in free_z3f= old_page and z3fold_page_migrate? 3.Should we add page to the unbuddied list in z3fold_page_putback() when z= hdr->refcount does not reach 0 since we remove it from unbuddied list in z3fold_page_isolate? Or When we will add page to the unbuddied list afte= r z3fold_page_putback? Thanks a lot in advance. And waiting for your reply. :)