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=-2.5 required=3.0 tests=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 1F60AC5DF60 for ; Fri, 8 Nov 2019 09:18:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DE84B2178F for ; Fri, 8 Nov 2019 09:18:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE84B2178F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 67CC16B0006; Fri, 8 Nov 2019 04:18:55 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 62D846B0008; Fri, 8 Nov 2019 04:18:55 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5438D6B000A; Fri, 8 Nov 2019 04:18:55 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0092.hostedemail.com [216.40.44.92]) by kanga.kvack.org (Postfix) with ESMTP id 3F90A6B0006 for ; Fri, 8 Nov 2019 04:18:55 -0500 (EST) Received: from smtpin25.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id F3BB88249980 for ; Fri, 8 Nov 2019 09:18:54 +0000 (UTC) X-FDA: 76132560630.25.board41_6ae67d68fab3a X-HE-Tag: board41_6ae67d68fab3a X-Filterd-Recvd-Size: 2688 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Fri, 8 Nov 2019 09:18:54 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 0BBD5B216; Fri, 8 Nov 2019 09:18:53 +0000 (UTC) Date: Fri, 8 Nov 2019 10:18:51 +0100 From: Michal Hocko To: Toshiki Fukasawa Cc: "linux-mm@kvack.org" , "dan.j.williams@intel.com" , "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 Message-ID: <20191108091851.GB15658@dhcp22.suse.cz> References: <20191108000855.25209-1-t-fukasawa@vx.jp.nec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191108000855.25209-1-t-fukasawa@vx.jp.nec.com> User-Agent: Mutt/1.10.1 (2018-07-13) 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 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? > > Toshiki Fukasawa (3): > procfs: refactor kpage_*_read() in fs/proc/page.c > mm: Introduce subsection_dev_map > mm: make pfn walker support ZONE_DEVICE > > fs/proc/page.c | 155 ++++++++++++++++++++--------------------------- > include/linux/memremap.h | 6 ++ > include/linux/mmzone.h | 19 ++++++ > mm/memremap.c | 31 ++++++++++ > mm/sparse.c | 32 ++++++++++ > 5 files changed, 154 insertions(+), 89 deletions(-) > > -- > 1.8.3.1 > -- Michal Hocko SUSE Labs