From: Sumanth Korikkar sumanthk@linux.ibm.com
[ Upstream commit c3576889d87b603cb66b417e08844a53c1077a37 ]
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/20250807183545.1424509-1-sumanthk@linux.ibm.com Fixes: 15995a352474 ("mm: report per-page metadata information") Signed-off-by: Sumanth Korikkar sumanthk@linux.ibm.com Suggested-by: David Hildenbrand david@redhat.com Reviewed-by: Wei Yang richard.weiyang@gmail.com Cc: Alexander Gordeev agordeev@linux.ibm.com Cc: Gerald Schaefer gerald.schaefer@linux.ibm.com Cc: Heiko Carstens hca@linux.ibm.com Cc: Vasily Gorbik gor@linux.ibm.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- mm/sparse-vmemmap.c | 5 ----- mm/sparse.c | 15 +++++++++------ 2 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index c0388b2e959da..2628fc02be08b 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -474,10 +474,5 @@ struct page * __meminit __populate_section_memmap(unsigned long pfn, if (r < 0) return NULL;
- if (system_state == SYSTEM_BOOTING) - memmap_boot_pages_add(DIV_ROUND_UP(end - start, PAGE_SIZE)); - else - memmap_pages_add(DIV_ROUND_UP(end - start, PAGE_SIZE)); - return pfn_to_page(pfn); } diff --git a/mm/sparse.c b/mm/sparse.c index dc38539f85603..eb6c5cb27ed1e 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -462,9 +462,6 @@ 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) @@ -532,6 +529,8 @@ 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)); check_usemap_section_nr(nid, usage); sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage, SECTION_IS_EARLY); @@ -643,7 +642,6 @@ 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) @@ -819,10 +817,14 @@ 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; @@ -867,6 +869,7 @@ 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; }