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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 2896BC4361B for ; Mon, 14 Dec 2020 11:14:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3E17229C6 for ; Mon, 14 Dec 2020 11:14:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729973AbgLNLOF (ORCPT ); Mon, 14 Dec 2020 06:14:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:56544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731657AbgLNLNK (ORCPT ); Mon, 14 Dec 2020 06:13:10 -0500 Date: Mon, 14 Dec 2020 13:12:21 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1607944349; bh=GkRrfJbxH307o+eT9bWI7gk2D73iFU3r1RvrpZL02pM=; h=From:To:Cc:Subject:References:In-Reply-To:From; b=R2ZYB6PBI6bnwZjdvz27i+v8m3w1cq6k3XJELsdi97OX8rTODm8XSm94tRVCbMJhd VQeOUL22Sjqm0mzD6VMgmt42Gr8+x9BvZYd7whTBofFXpdhV0Ct2lIU4VweVfwhRuG Tyogu3ZvPDKM6X6AcPjlwa5cUseISLUmhiEiM6liwYp24hADm2p9Nsiozh+J31t32b zeVcgwRUbOuLFekmpw/5W57EkEdOp2cL/b4RBikd6JWi4k/rKm6Joj0RgM9BlMRPf5 LuTzfkY280axXFZmFpmuqdU91/Kr7JU2Y/2kLffUJcI7M7hse+3lNZ22T+UwBaoLkd AzvOFu6ZELC8A== From: Mike Rapoport To: David Hildenbrand Cc: Andrew Morton , Andrea Arcangeli , Baoquan He , Mel Gorman , Michal Hocko , Mike Rapoport , Qian Cai , Vlastimil Babka , linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, Dan Williams Subject: Re: [PATCH v2 1/2] mm: memblock: enforce overlap of memory.memblock and memory.reserved Message-ID: <20201214111221.GC198219@kernel.org> References: <20201209214304.6812-1-rppt@kernel.org> <20201209214304.6812-2-rppt@kernel.org> <522640a5-32ab-2247-4c2a-f248c2528f97@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <522640a5-32ab-2247-4c2a-f248c2528f97@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 14, 2020 at 11:11:35AM +0100, David Hildenbrand wrote: > On 09.12.20 22:43, Mike Rapoport wrote: > > From: Mike Rapoport > > > > memblock does not require that the reserved memory ranges will be a subset > > of memblock.memory. > > > > As the result there maybe reserved pages that are not in the range of any > > zone or node because zone and node boundaries are detected based on > > memblock.memory and pages that only present in memblock.reserved are not > > taken into account during zone/node size detection. > > > > Make sure that all ranges in memblock.reserved are added to memblock.memory > > before calculating node and zone boundaries. > > > > Fixes: 73a6e474cb37 ("mm: memmap_init: iterate over memblock regions rather that check each PFN") > > Reported-by: Andrea Arcangeli > > Signed-off-by: Mike Rapoport > > --- > > include/linux/memblock.h | 1 + > > mm/memblock.c | 24 ++++++++++++++++++++++++ > > mm/page_alloc.c | 7 +++++++ > > 3 files changed, 32 insertions(+) > > > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > > index ef131255cedc..e64dae2dd1ce 100644 > > --- a/include/linux/memblock.h > > +++ b/include/linux/memblock.h > > @@ -120,6 +120,7 @@ int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); > > unsigned long memblock_free_all(void); > > void reset_node_managed_pages(pg_data_t *pgdat); > > void reset_all_zones_managed_pages(void); > > +void memblock_enforce_memory_reserved_overlap(void); > > > > /* Low level functions */ > > void __next_mem_range(u64 *idx, int nid, enum memblock_flags flags, > > diff --git a/mm/memblock.c b/mm/memblock.c > > index b68ee86788af..9277aca642b2 100644 > > --- a/mm/memblock.c > > +++ b/mm/memblock.c > > @@ -1857,6 +1857,30 @@ void __init_memblock memblock_trim_memory(phys_addr_t align) > > } > > } > > > > +/** > > + * memblock_enforce_memory_reserved_overlap - make sure every range in > > + * @memblock.reserved is covered by @memblock.memory > > + * > > + * The data in @memblock.memory is used to detect zone and node boundaries > > + * during initialization of the memory map and the page allocator. Make > > + * sure that every memory range present in @memblock.reserved is also added > > + * to @memblock.memory even if the architecture specific memory > > + * initialization failed to do so > > + */ > > +void __init memblock_enforce_memory_reserved_overlap(void) > > +{ > > + phys_addr_t start, end; > > + int nid; > > + u64 i; > > + > > + __for_each_mem_range(i, &memblock.reserved, &memblock.memory, > > + NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, &nid) { > > + pr_warn("memblock: reserved range [%pa-%pa] is not in memory\n", > > + &start, &end); > > + memblock_add_node(start, (end - start), nid); > > + } > > +} > > + > > void __init_memblock memblock_set_current_limit(phys_addr_t limit) > > { > > memblock.current_limit = limit; > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > > index eaa227a479e4..dbc57dbbacd8 100644 > > --- a/mm/page_alloc.c > > +++ b/mm/page_alloc.c > > @@ -7436,6 +7436,13 @@ void __init free_area_init(unsigned long *max_zone_pfn) > > memset(arch_zone_highest_possible_pfn, 0, > > sizeof(arch_zone_highest_possible_pfn)); > > > > + /* > > + * Some architectures (e.g. x86) have reserved pages outside of > > + * memblock.memory. Make sure these pages are taken into account > > + * when detecting zone and node boundaries > > + */ > > + memblock_enforce_memory_reserved_overlap(); > > + > > start_pfn = find_min_pfn_with_active_regions(); > > descending = arch_has_descending_max_zone_pfns(); > > > > > > CCing Dan. > > This implies that any memory that is E820_TYPE_SOFT_RESERVED that was > reserved via memblock_reserve() will be added via memblock_add_node() as > well, resulting in all such memory getting a memmap allocated right when > booting up, right? > > IIRC, there are use cases where that is absolutely not desired. Hmm, if this is the case we need entirely different solution to ensure that we don't have partial pageblocks in a zone and we have all the memory map initialized to a known state. > Am I missing something? (@Dan?) BTW, @Dan, why did you need to memblock_reserve(E820_TYPE_SOFT_RESERVED) without memblock_add()ing it? > -- > Thanks, > > David / dhildenb > -- Sincerely yours, Mike.