From patchwork Wed Jan 13 07:35:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 12015969 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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=ham 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 CBF15C433E0 for ; Wed, 13 Jan 2021 07:35:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2436F2085B for ; Wed, 13 Jan 2021 07:35:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2436F2085B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 406D96B00C4; Wed, 13 Jan 2021 02:35:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 38F116B00C5; Wed, 13 Jan 2021 02:35:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 27FB66B00C6; Wed, 13 Jan 2021 02:35:23 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0199.hostedemail.com [216.40.44.199]) by kanga.kvack.org (Postfix) with ESMTP id 046836B00C4 for ; Wed, 13 Jan 2021 02:35:23 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id B855C181AEF2A for ; Wed, 13 Jan 2021 07:35:22 +0000 (UTC) X-FDA: 77699941284.20.plane09_310137a2751c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 95AF0180C07A3 for ; Wed, 13 Jan 2021 07:35:22 +0000 (UTC) X-HE-Tag: plane09_310137a2751c X-Filterd-Recvd-Size: 4720 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Wed, 13 Jan 2021 07:35:21 +0000 (UTC) IronPort-SDR: 9V9eiq8UtBao+qOwOvzqcFBFzK0sJ8H1LQTcB7NpVeVNF1qC63ZCD3FA39et2/ujjzdNM2KGQC O5Vv/vSFKj1g== X-IronPort-AV: E=McAfee;i="6000,8403,9862"; a="177387869" X-IronPort-AV: E=Sophos;i="5.79,343,1602572400"; d="scan'208";a="177387869" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2021 23:35:19 -0800 IronPort-SDR: R7U7SOlxIAask0dFOPSZ+iv/4TSvK3885rmAPXftCa0I6o/KodFyfMs5MpYz6914ji5DT++mEY igedmqs3aGCA== X-IronPort-AV: E=Sophos;i="5.79,343,1602572400"; d="scan'208";a="400456436" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.25]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2021 23:35:15 -0800 Subject: [PATCH v3 0/6] mm: Fix pfn_to_online_page() with respect to ZONE_DEVICE From: Dan Williams To: linux-mm@kvack.org Cc: David Hildenbrand , Dave Jiang , Ira Weiny , stable@vger.kernel.org, Naoya Horiguchi , Qian Cai , Michal Hocko , Oscar Salvador , Michal Hocko , Naoya Horiguchi , Vishal Verma , Andrew Morton , linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org Date: Tue, 12 Jan 2021 23:35:15 -0800 Message-ID: <161052331545.1805594.2356512831689786960.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 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: Changes since v2 [1]: - Collect some reviewed-by's from David and Oscar - Rework subsection validity to include pfn_valid() gated by CONFIG_HAVE_ARCH_PFN_VALID (David, Oscar) - Introduce pgmap_pfn_valid() to validate metadata vs data in a pgmap (David) ! Kill put_ref_page(): the extra "if (ref_page) put_page(ref_page)" still feels more cluttered than adding a tiny helper. (Oscar) [1]: http://lore.kernel.org/r/161044407603.1482714.16630477578392768273.stgit@dwillia2-desk3.amr.corp.intel.com --- Michal reminds that the discussion about how to ensure pfn-walkers do not get confused by ZONE_DEVICE pages never resolved. A pfn-walker that uses pfn_to_online_page() may inadvertently translate a pfn as online and in the page allocator, when it is offline managed by a ZONE_DEVICE mapping (details in Patch 3: ("mm: Teach pfn_to_online_page() about ZONE_DEVICE section collisions")). The 2 proposals under consideration are teach pfn_to_online_page() to be precise in the presence of mixed-zone sections, or teach the memory-add code to drop the System RAM associated with ZONE_DEVICE collisions. In order to not regress memory capacity by a few 10s to 100s of MiB the approach taken in this set is to add precision to pfn_to_online_page(). In the course of validating pfn_to_online_page() a couple other fixes fell out: 1/ soft_offline_page() fails to drop the reference taken in the madvise(..., MADV_SOFT_OFFLINE) case. 2/ The libnvdimm sysfs attribute visibility code was failing to publish the resource base for memmap=ss!nn defined namespaces. This is needed for the regression test for soft_offline_page(). 3/ memory_failure() uses get_dev_pagemap() to lookup ZONE_DEVICE pages, however that mapping may contain data pages and metadata raw pfns. Introduce pgmap_pfn_valid() to delineate the 2 types and fail the handling of raw metadata pfns. --- Dan Williams (6): mm: Move pfn_to_online_page() out of line mm: Teach pfn_to_online_page() to consider subsection validity mm: Teach pfn_to_online_page() about ZONE_DEVICE section collisions mm: Fix page reference leak in soft_offline_page() mm: Fix memory_failure() handling of dax-namespace metadata libnvdimm/namespace: Fix visibility of namespace resource attribute drivers/nvdimm/namespace_devs.c | 10 +++--- include/linux/memory_hotplug.h | 17 +-------- include/linux/memremap.h | 6 +++ include/linux/mmzone.h | 22 ++++++++---- mm/memory-failure.c | 26 ++++++++++++-- mm/memory_hotplug.c | 70 +++++++++++++++++++++++++++++++++++++++ mm/memremap.c | 15 ++++++++ 7 files changed, 134 insertions(+), 32 deletions(-)