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-memorymemblock-and-memoryreserved.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-memblock-enforce-overlap-of-memorymemblock-and-memoryreserved.patch
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------------------------------------------------------
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
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@xxxxxx
[2] https://lore.kernel.org/lkml/20201121194506.13464-1-aarcange@xxxxxxxxxx
[3] https://lore.kernel.org/mm-commits/20201206005401.qKuAVgOXr%akpm@xxxxxxxxxxxxxxxxxxxx
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@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20201209214304.6812-2-rppt@xxxxxxxxxx
Fixes: 73a6e474cb37 ("mm: memmap_init: iterate over memblock regions rather that check each PFN")
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Reported-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Qian Cai <cai@xxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxxxxx 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
