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=-0.8 required=3.0 tests=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 90EC0C43331 for ; Mon, 11 Nov 2019 08:02:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D30520679 for ; Mon, 11 Nov 2019 08:02:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727015AbfKKICE convert rfc822-to-8bit (ORCPT ); Mon, 11 Nov 2019 03:02:04 -0500 Received: from tyo162.gate.nec.co.jp ([114.179.232.162]:35478 "EHLO tyo162.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726834AbfKKICE (ORCPT ); Mon, 11 Nov 2019 03:02:04 -0500 Received: from mailgate02.nec.co.jp ([114.179.233.122]) by tyo162.gate.nec.co.jp (8.15.1/8.15.1) with ESMTPS id xAB81YtL004733 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 11 Nov 2019 17:01:34 +0900 Received: from mailsv02.nec.co.jp (mailgate-v.nec.co.jp [10.204.236.94]) by mailgate02.nec.co.jp (8.15.1/8.15.1) with ESMTP id xAB81XoH029777; Mon, 11 Nov 2019 17:01:33 +0900 Received: from mail01b.kamome.nec.co.jp (mail01b.kamome.nec.co.jp [10.25.43.2]) by mailsv02.nec.co.jp (8.15.1/8.15.1) with ESMTP id xAB7xwjS001591; Mon, 11 Nov 2019 17:01:33 +0900 Received: from bpxc99gp.gisp.nec.co.jp ([10.38.151.152] [10.38.151.152]) by mail03.kamome.nec.co.jp with ESMTP id BT-MMP-641210; Mon, 11 Nov 2019 17:00:13 +0900 Received: from BPXM20GP.gisp.nec.co.jp ([10.38.151.212]) by BPXC24GP.gisp.nec.co.jp ([10.38.151.152]) with mapi id 14.03.0439.000; Mon, 11 Nov 2019 17:00:13 +0900 From: Toshiki Fukasawa To: Michal Hocko , "dan.j.williams@intel.com" CC: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "adobriyan@gmail.com" , "hch@lst.de" , "longman@redhat.com" , "sfr@canb.auug.org.au" , "mst@redhat.com" , "cai@lca.pw" , Naoya Horiguchi , Junichi Nomura Subject: Re: [PATCH 0/3] make pfn walker support ZONE_DEVICE Thread-Topic: [PATCH 0/3] make pfn walker support ZONE_DEVICE Thread-Index: AQHVlciWlfuQn46br0aHiPqwVpeT66eAaKCAgAShS4A= Date: Mon, 11 Nov 2019 08:00:12 +0000 Message-ID: <5fc7da0c-bd79-9f3b-e5d9-8688648cf032@vx.jp.nec.com> References: <20191108000855.25209-1-t-fukasawa@vx.jp.nec.com> <20191108091851.GB15658@dhcp22.suse.cz> In-Reply-To: <20191108091851.GB15658@dhcp22.suse.cz> Accept-Language: ja-JP, en-US Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.34.125.135] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: <08075FF5519BA149B29FF17900429CC7@gisp.nec.co.jp> Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/11/08 18:18, Michal Hocko wrote: > On Fri 08-11-19 00:08:03, Toshiki Fukasawa wrote: >> This patch set tries to make pfn walker support ZONE_DEVICE. >> This idea is from the TODO in below patch: >> >> commit aad5f69bc161af489dbb5934868bd347282f0764 >> Author: David Hildenbrand >> Date: Fri Oct 18 20:19:20 2019 -0700 >> >> fs/proc/page.c: don't access uninitialized memmaps in fs/proc/page.c >> >> pfn walker's ZONE_DEVICE support requires capability to identify >> that a memmap has been initialized. The uninitialized cases are >> as follows: >> >> a) pages reserved for ZONE_DEVICE driver >> b) pages currently initializing >> >> This patch set solves both of them. > > Why do we want this? What is the usecase? We are writing a test program for hwpoison, which is a use case. Without this patch, we can't see the HWPOISON flag on the ZONE_DEVICE page. Thanks, Toshiki Fukasawa