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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 6B4E3C433E0 for ; Mon, 22 Feb 2021 10:54:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D62FD64E5C for ; Mon, 22 Feb 2021 10:54:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D62FD64E5C 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 51BA36B0006; Mon, 22 Feb 2021 05:54:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4CA516B006C; Mon, 22 Feb 2021 05:54:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 408996B006E; Mon, 22 Feb 2021 05:54:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0160.hostedemail.com [216.40.44.160]) by kanga.kvack.org (Postfix) with ESMTP id 2C4536B0006 for ; Mon, 22 Feb 2021 05:54:12 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id D69598794 for ; Mon, 22 Feb 2021 10:54:11 +0000 (UTC) X-FDA: 77845594302.16.BEF75CA Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf14.hostedemail.com (Postfix) with ESMTP id 31F92C000C4B for ; Mon, 22 Feb 2021 10:54:05 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id CB87364E04; Mon, 22 Feb 2021 10:54:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613991250; bh=paRjSN108FmOvvi0TofHdKlKJPnvAiYjtvHzzEJsom4=; h=From:To:Cc:Subject:Date:From; b=FFFHN+N/hLrZCq8x2aBnXef3slLETnF/RqgxBhzLnGXwg/k8mSfS9VPLyXLshKmGf Qs3FewOVrp7jnwrcbaFXjChrPqq/5GfHYpS48erB0IavUYPcKKUdglyU+Z6emEH8sw vO+R3KQP8jhDGipZE4K0Hb9KmD04lz0bcC6FlPwSkoyVteMWARZr4aryKNT4mKkvLU La3L46MmuIzek9C0vYSg3n78fqWjKqp9IEgrX6/gvCwNC1vFlgvOn1Kcs5I9QmfTAU perId2YWM7ekxb66UQ3vntiMZOQqrvZUleN2Oq2CNupPrbt+74zDOJUmalC8UhfZCy v4jKQSpxPbL8Q== From: Mike Rapoport To: Andrew Morton Cc: Andrea Arcangeli , Baoquan He , Borislav Petkov , Chris Wilson , David Hildenbrand , "H. Peter Anvin" , Ingo Molnar , Linus Torvalds , =?UTF-8?q?=C5=81ukasz=20Majczak?= , Mel Gorman , Michal Hocko , Mike Rapoport , Mike Rapoport , Qian Cai , "Sarvela, Tomi P" , Thomas Gleixner , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, x86@kernel.org Subject: [PATCH v6 0/1] mm: fix initialization of struct page for holes in memory layout Date: Mon, 22 Feb 2021 12:54:00 +0200 Message-Id: <20210222105400.28583-1-rppt@kernel.org> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 X-Stat-Signature: x5rztd5emozhfs1nq39azs4wj6yonm8m X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 31F92C000C4B Received-SPF: none (kernel.org>: No applicable sender policy available) receiver=imf14; identity=mailfrom; envelope-from=""; helo=mail.kernel.org; client-ip=198.145.29.99 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1613991245-555109 Content-Transfer-Encoding: quoted-printable 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: From: Mike Rapoport Hi, @Andrew, this is based on v5.11-mmotm-2021-02-18-18-29 with the previous version reverted Commit 73a6e474cb37 ("mm: memmap_init: iterate over memblock regions rath= er that check each PFN") exposed several issues with the memory map initialization and these patches fix those issues. Initially there were crashes during compaction that Qian Cai reported bac= k in April [1]. It seemed back then that the problem was fixed, but a few weeks ago Andrea Arcangeli hit the same bug [2] and there was an addition= al discussion at [3]. I didn't appreciate variety of ways BIOSes can report memory in the first megabyte, so previous versions of this set caused all kinds of troubles. The last version that implicitly extended node/zone to cover the complete section might also have unexpected side effects, so this time I'm trying = to move in forward in baby steps. This is mostly a return to the fist version that simply merges init_unavailable_pages() into memmap_init() so that the only effective change would be more sensible zone/node links in unavailable struct pages= . For now, I've dropped the patch that tried to make ZONE_DMA to span pfn 0 because it didn't cause any issues for really long time and there are way to many hidden mines around this. I have an ugly workaround for "pfn 0" issue that IMHO is the safest way t= o deal with it until it could be gradually fixed properly: https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/commit/?id= =3Da1b6e4d7e4a6d893caeda9a7f3800766243a02fe v6: * only interleave initialization of unavailable pages in memmap_init(), s= o that it is essentially includes init_unavailable_pages(). v5: https://lore.kernel.org/lkml/20210208110820.6269-1-rppt@kernel.org * extend node/zone spans to cover complete sections, this allows to inter= leave the initialization of unavailable pages with "normal" memory map init. * drop modifications to x86 early setup v4: https://lore.kernel.org/lkml/20210130221035.4169-1-rppt@kernel.org/ * make sure pages in the range 0 - start_pfn_of_lowest_zone are initializ= ed even if an architecture hides them from the generic mm * finally make pfn 0 on x86 to be a part of memory visible to the generic mm as reserved memory. v3: https://lore.kernel.org/lkml/20210111194017.22696-1-rppt@kernel.org * use architectural zone constraints to set zone links for struct pages corresponding to the holes * drop implicit update of memblock.memory * add a patch that sets pfn 0 to E820_TYPE_RAM on x86 v2: https://lore.kernel.org/lkml/20201209214304.6812-1-rppt@kernel.org/): * added patch that adds all regions in memblock.reserved that do not overlap with memblock.memory to memblock.memory in the beginning of free_area_init() [1] https://lore.kernel.org/lkml/8C537EB7-85EE-4DCF-943E-3CC0ED0DF56D@lca= .pw [2] https://lore.kernel.org/lkml/20201121194506.13464-1-aarcange@redhat.c= om [3] https://lore.kernel.org/mm-commits/20201206005401.qKuAVgOXr%akpm@linu= x-foundation.org Mike Rapoport (1): mm/page_alloc.c: refactor initialization of struct page for holes in memory layout mm/page_alloc.c | 144 ++++++++++++++++++++---------------------------- 1 file changed, 61 insertions(+), 83 deletions(-) --=20 2.28.0