Teach section_nr_vmemmap_pages() to account for section-based vmemmap optimization, so the helper can report the vmemmap page usage for a memory section with or without shared tail vmemmap pages.
Signed-off-by: Muchun Song <[email protected]> --- include/linux/mmzone.h | 8 ++++++++ mm/sparse-vmemmap.c | 13 +++++++++---- 2 files changed, 17 insertions(+), 4 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 5fc968bac1f7..0974205abd3d 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -2269,6 +2269,14 @@ static inline unsigned int pfn_to_section_order(unsigned long pfn) return section_order(__pfn_to_section(pfn)); } +static inline bool section_vmemmap_optimizable(const struct mem_section *section) +{ + if (!is_power_of_2(sizeof(struct page))) + return false; + + return section_order(section) >= OPTIMIZABLE_FOLIO_MIN_ORDER; +} + void sparse_init_early_section(int nid, struct page *map, unsigned long pnum, unsigned long flags); diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 60d5330a8399..94964363d95c 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -629,24 +629,29 @@ void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn) static int __meminit section_nr_vmemmap_pages(unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap, struct dev_pagemap *pgmap) { - const unsigned int order = pgmap ? pgmap->vmemmap_shift : 0; + const struct mem_section *ms = __pfn_to_section(pfn); + const unsigned int order = pgmap ? pgmap->vmemmap_shift : section_order(ms); const unsigned long pages_per_compound = 1UL << order; + unsigned int vmemmap_pages = OPTIMIZED_FOLIO_VMEMMAP_PAGES; VM_WARN_ON_ONCE(!IS_ALIGNED(pfn | nr_pages, PAGES_PER_SUBSECTION)); VM_WARN_ON_ONCE(nr_pages > PAGES_PER_SECTION); - if (!vmemmap_can_optimize(altmap, pgmap)) + if (vmemmap_can_optimize(altmap, pgmap)) + vmemmap_pages = VMEMMAP_RESERVE_NR; + + if (!vmemmap_can_optimize(altmap, pgmap) && !section_vmemmap_optimizable(ms)) return DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE); if (order < PFN_SECTION_SHIFT) { VM_WARN_ON_ONCE(!IS_ALIGNED(pfn | nr_pages, pages_per_compound)); - return VMEMMAP_RESERVE_NR * nr_pages / pages_per_compound; + return vmemmap_pages * nr_pages / pages_per_compound; } VM_WARN_ON_ONCE(!IS_ALIGNED(pfn | nr_pages, PAGES_PER_SECTION)); if (IS_ALIGNED(pfn, pages_per_compound)) - return VMEMMAP_RESERVE_NR; + return vmemmap_pages; return 0; } -- 2.54.0
