From 4af04bd8121fbd44891e6db2ca138c6d739b1f82 Mon Sep 17 00:00:00 2001 From: "David Hildenbrand (Arm)" Date: Mon, 21 Sep 2026 21:59:00 +0200 Subject: [PATCH] mm/sparse: move __highest_used_section_nr handling In preparation for removing __section_mark_present(), let's move __highest_used_section_nr handling into its callers. Verify in sparse_init_one_section() that it was properly updated. In sparse_sections_init() we can just set it to the last processed section_nr. No functional change intended. Link: https://lore.kernel.org/20260921-b4-sparsemem_cleanups-v2-8-54d81d65e125@kernel.org Signed-off-by: David Hildenbrand (Arm) Signed-off-by: Andrew Morton Reviewed-by: Mike Rapoport (Microsoft) Acked-by: Oscar Salvador Cc: Lorenzo Stoakes Cc: Liam R. Howlett Cc: Vlastimil Babka Cc: Suren Baghdasaryan Cc: Michal Hocko Cc: Kairui Song Cc: Qi Zheng Cc: Shakeel Butt Cc: Barry Song Cc: Axel Rasmussen Cc: Yuanchu Xie Cc: Wei Xu Cc: Baoquan He Cc: Baolin Wang Cc: Brendan Jackman Cc: Johannes Weiner Cc: Zi Yan Cc: Jan Kiszka Cc: Kieran Bingham Cc: Greg Kroah-Hartman Cc: Rafael J. Wysocki Cc: Danilo Krummrich --- mm/sparse-vmemmap.c | 1 + mm/sparse.c | 5 +++-- mm/sparse.h | 4 +--- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 23b31bc4bf94..d5fd61c83bac 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -904,6 +904,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, page_init_poison(memmap, sizeof(struct page) * nr_pages); __section_mark_present(ms, section_nr); + __highest_used_section_nr = max(section_nr, __highest_used_section_nr); /* Align memmap to section boundary in the subsection case */ if (section_nr_to_pfn(section_nr) != start_pfn) diff --git a/mm/sparse.c b/mm/sparse.c index bb89017254f4..a0f50ca5acf5 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -177,7 +177,7 @@ static inline unsigned long first_present_section_nr(void) void __init sparse_sections_init(void) { - unsigned long pfn, start_pfn, end_pfn; + unsigned long pfn, start_pfn, end_pfn, section_nr; int i, nid; sparse_extreme_init(); @@ -187,9 +187,9 @@ void __init sparse_sections_init(void) mminit_validate_memmodel_limits(&start_pfn, &end_pfn); for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { - unsigned long section_nr = pfn_to_section_nr(pfn); struct mem_section *ms; + section_nr = pfn_to_section_nr(pfn); sparse_index_init(section_nr, nid); ms = __nr_to_section(section_nr); if (ms->section_mem_map) @@ -201,6 +201,7 @@ void __init sparse_sections_init(void) __section_mark_present(ms, section_nr); } } + __highest_used_section_nr = section_nr; } #ifndef CONFIG_SPARSEMEM_VMEMMAP struct page __init *__populate_section_memmap(unsigned long pfn, diff --git a/mm/sparse.h b/mm/sparse.h index 242b7bab0013..c396d5c05cfc 100644 --- a/mm/sparse.h +++ b/mm/sparse.h @@ -26,6 +26,7 @@ static inline void sparse_init_one_section(struct mem_section *ms, unsigned long coded_mem_map; BUILD_BUG_ON(SECTION_MAP_LAST_BIT > PFN_SECTION_SHIFT); + VM_WARN_ON_ONCE(section_nr > __highest_used_section_nr); /* * We encode the start PFN of the section into the mem_map such that @@ -44,9 +45,6 @@ static inline void sparse_init_one_section(struct mem_section *ms, static inline void __section_mark_present(struct mem_section *ms, unsigned long section_nr) { - if (section_nr > __highest_used_section_nr) - __highest_used_section_nr = section_nr; - ms->section_mem_map |= SECTION_MARKED_PRESENT; }