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. Signed-off-by: Sumanth Korikkar --- v3: * Account memmap pages for !CONFIG_SPARSEMEM_VMEMMAP and only when memmap allocation succeeds. Thanks Wei Yang. v2: * Account memmap pages for !CONFIG_SPARSEMEM_VMEMMAP in section_deactivate(). Thanks David. * https://lore.kernel.org/all/20250804151328.2326642-1-sumanthk@linux.ibm.com/ v1: * Account memmap pages for early sections. * https://lore.kernel.org/all/20250804084015.270570-1-sumanthk@linux.ibm.com/ 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 fd2ab5118e13..41aa0493eb03 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -578,11 +578,6 @@ 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 066cbf82acb8..24323122f6cb 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; } -- 2.48.1