The patch titled Subject: mm: memblock: enforce overlap of memory.memblock and memory.reserved has been added to the -mm tree. Its filename is mm-memblock-enforce-overlap-of-memorymemblock-and-memoryreserved.patch

This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-memblock-enforce-overlap-of-mem... and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-memblock-enforce-overlap-of-mem...

Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated there every 3-4 working days

------------------------------------------------------ From: Mike Rapoport rppt@linux.ibm.com Subject: mm: memblock: enforce overlap of memory.memblock and memory.reserved

Patch series "mm: fix initialization of struct page for holes in memory layout", v2.

Commit 73a6e474cb37 ("mm: memmap_init: iterate over memblock regions rather 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 back in April [1]. It seemed back then that the probelm was fixed, but a few weeks ago Andrea Arcangeli hit the same bug [2] and after a long discussion between us [3] I think these patches are the proper fix.

[1] https://lore.kernel.org/lkml/8C537EB7-85EE-4DCF-943E-3CC0ED0DF56D@lca.pw [2] https://lore.kernel.org/lkml/20201121194506.13464-1-aarcange@redhat.com [3] https://lore.kernel.org/mm-commits/20201206005401.qKuAVgOXr%akpm@linux-found...

This patch (of 2):

memblock does not require that the reserved memory ranges will be a subset of memblock.memory.

As a result there may be 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.

Link: https://lkml.kernel.org/r/20201209214304.6812-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20201209214304.6812-2-rppt@kernel.org Fixes: 73a6e474cb37 ("mm: memmap_init: iterate over memblock regions rather that check each PFN") Signed-off-by: Mike Rapoport rppt@linux.ibm.com Reported-by: Andrea Arcangeli aarcange@redhat.com Cc: Baoquan He bhe@redhat.com Cc: David Hildenbrand david@redhat.com Cc: Mel Gorman mgorman@suse.de Cc: Michal Hocko mhocko@kernel.org Cc: Qian Cai cai@lca.pw Cc: Vlastimil Babka vbabka@suse.cz Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

include/linux/memblock.h | 1 + mm/memblock.c | 24 ++++++++++++++++++++++++ mm/page_alloc.c | 7 +++++++ 3 files changed, 32 insertions(+)

--- a/include/linux/memblock.h~mm-memblock-enforce-overlap-of-memorymemblock-and-memoryreserved +++ a/include/linux/memblock.h @@ -120,6 +120,7 @@ int memblock_clear_nomap(phys_addr_t bas 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, --- a/mm/memblock.c~mm-memblock-enforce-overlap-of-memorymemblock-and-memoryreserved +++ a/mm/memblock.c @@ -1857,6 +1857,30 @@ void __init_memblock memblock_trim_memor } }

+/** + * 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; --- a/mm/page_alloc.c~mm-memblock-enforce-overlap-of-memorymemblock-and-memoryreserved +++ a/mm/page_alloc.c @@ -7507,6 +7507,13 @@ void __init free_area_init(unsigned long 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();

_

Patches currently in -mm which might be from rppt@linux.ibm.com are

alpha-switch-from-discontigmem-to-sparsemem.patch ia64-remove-custom-__early_pfn_to_nid.patch ia64-remove-ifdef-config_zone_dma32-statements.patch ia64-discontig-paging_init-remove-local-max_pfn-calculation.patch ia64-split-virtual-map-initialization-out-of-paging_init.patch ia64-forbid-using-virtual_mem_map-with-flatmem.patch ia64-make-sparsemem-default-and-disable-discontigmem.patch arm-remove-config_arch_has_holes_memorymodel.patch arm-arm64-move-free_unused_memmap-to-generic-mm.patch arc-use-flatmem-with-freeing-of-unused-memory-map-instead-of-discontigmem.patch m68k-mm-make-node-data-and-node-setup-depend-on-config_discontigmem.patch m68k-mm-enable-use-of-generic-memory_modelh-for-discontigmem.patch m68k-deprecate-discontigmem.patch mm-introduce-debug_pagealloc_mapunmap_pages-helpers.patch pm-hibernate-make-direct-map-manipulations-more-explicit.patch arch-mm-restore-dependency-of-__kernel_map_pages-on-debug_pagealloc.patch arch-mm-make-kernel_page_present-always-available.patch mm-memblock-enforce-overlap-of-memorymemblock-and-memoryreserved.patch mm-fix-initialization-of-struct-page-for-holes-in-memory-layout.patch mm-add-definition-of-pmd_page_order.patch mmap-make-mlock_future_check-global.patch set_memory-allow-set_direct_map__noflush-for-multiple-pages.patch set_memory-allow-querying-whether-set_direct_map_-is-actually-enabled.patch mm-introduce-memfd_secret-system-call-to-create-secret-memory-areas.patch secretmem-use-pmd-size-pages-to-amortize-direct-map-fragmentation.patch secretmem-add-memcg-accounting.patch pm-hibernate-disable-when-there-are-active-secretmem-users.patch arch-mm-wire-up-memfd_secret-system-call-were-relevant.patch secretmem-test-add-basic-selftest-for-memfd_secret2.patch