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authorSumanth Korikkar <[email protected]>2025-08-07 18:35:45 +0000
committerAndrew Morton <[email protected]>2025-08-28 05:45:43 +0000
commitc3576889d87b603cb66b417e08844a53c1077a37 (patch)
tree8b7a41c86d02281522b376043422c2417f9dfd5b /mm/sparse.c
parentmm/damon/core: prevent unnecessary overflow in damos_set_effective_quota() (diff)
downloadkernel-c3576889d87b603cb66b417e08844a53c1077a37.tar.gz
kernel-c3576889d87b603cb66b417e08844a53c1077a37.zip
mm: fix accounting of memmap pages
For !CONFIG_SPARSEMEM_VMEMMAP, memmap page accounting is currently done upfront in sparse_buffer_init(). However, sparse_buffer_alloc() may return NULL in failure scenario. Also, memmap pages may be allocated either from the memblock allocator during early boot or from the buddy allocator. When removed via arch_remove_memory(), accounting of memmap pages must reflect the original allocation source. To ensure correctness: * Account memmap pages after successful allocation in sparse_init_nid() and section_activate(). * Account memmap pages in section_deactivate() based on allocation source. Link: https://lkml.kernel.org/r/[email protected] Fixes: 15995a352474 ("mm: report per-page metadata information") Signed-off-by: Sumanth Korikkar <[email protected]> Suggested-by: David Hildenbrand <[email protected]> Reviewed-by: Wei Yang <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Gerald Schaefer <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
Diffstat (limited to 'mm/sparse.c')
-rw-r--r--mm/sparse.c15
1 files changed, 9 insertions, 6 deletions
diff --git a/mm/sparse.c b/mm/sparse.c
index 3c012cf83cc2..e6075b622407 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -454,9 +454,6 @@ static void __init sparse_buffer_init(unsigned long size, int nid)
*/
sparsemap_buf = memmap_alloc(size, section_map_size(), addr, nid, true);
sparsemap_buf_end = sparsemap_buf + size;
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
- memmap_boot_pages_add(DIV_ROUND_UP(size, PAGE_SIZE));
-#endif
}
static void __init sparse_buffer_fini(void)
@@ -567,6 +564,8 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
sparse_buffer_fini();
goto failed;
}
+ memmap_boot_pages_add(DIV_ROUND_UP(PAGES_PER_SECTION * sizeof(struct page),
+ PAGE_SIZE));
sparse_init_early_section(nid, map, pnum, 0);
}
}
@@ -680,7 +679,6 @@ static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
unsigned long start = (unsigned long) pfn_to_page(pfn);
unsigned long end = start + nr_pages * sizeof(struct page);
- memmap_pages_add(-1L * (DIV_ROUND_UP(end - start, PAGE_SIZE)));
vmemmap_free(start, end, altmap);
}
static void free_map_bootmem(struct page *memmap)
@@ -856,10 +854,14 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
* The memmap of early sections is always fully populated. See
* section_activate() and pfn_valid() .
*/
- if (!section_is_early)
+ if (!section_is_early) {
+ memmap_pages_add(-1L * (DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE)));
depopulate_section_memmap(pfn, nr_pages, altmap);
- else if (memmap)
+ } else if (memmap) {
+ memmap_boot_pages_add(-1L * (DIV_ROUND_UP(nr_pages * sizeof(struct page),
+ PAGE_SIZE)));
free_map_bootmem(memmap);
+ }
if (empty)
ms->section_mem_map = (unsigned long)NULL;
@@ -904,6 +906,7 @@ static struct page * __meminit section_activate(int nid, unsigned long pfn,
section_deactivate(pfn, nr_pages, altmap);
return ERR_PTR(-ENOMEM);
}
+ memmap_pages_add(DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE));
return memmap;
}