From da7acb8982edf70078b23f878c6b8f2b496abdb5 Mon Sep 17 00:00:00 2001 From: "David Hildenbrand (Arm)" Date: Mon, 21 Sep 2026 21:59:02 +0200 Subject: [PATCH] mm/sparse: remove SECTION_MARKED_PRESENT All present section iterators run before memory hotplug added any further memory sections, Therefore, we can simply use the SECTION_IS_EARLY flag by setting that flag earlier in sparse_sections_init(). Get rid of SECTION_MARKED_PRESENT entirely and rename for_each_present_section_nr() to for_each_early_section_nr(). Take care of the .clang-format for_each_present_section_nr() handling. No functional change intended. Link: https://lore.kernel.org/20260921-b4-sparsemem_cleanups-v2-10-54d81d65e125@kernel.org Signed-off-by: David Hildenbrand (Arm) Signed-off-by: Andrew Morton Acked-by: Oscar Salvador Acked-by: Lorenzo Stoakes (ARM) Reviewed-by: Mike Rapoport (Microsoft) 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 --- .clang-format | 2 +- drivers/base/memory.c | 2 +- include/linux/mmzone.h | 27 ++++++++++----------------- mm/sparse-vmemmap.c | 1 - mm/sparse.c | 17 ++++++++--------- mm/sparse.h | 6 ------ 6 files changed, 20 insertions(+), 35 deletions(-) diff --git a/.clang-format b/.clang-format index 5ef5743b77c9..395292ab2ac6 100644 --- a/.clang-format +++ b/.clang-format @@ -282,6 +282,7 @@ ForEachMacros: - 'for_each_dpcm_fe' - 'for_each_drhd_unit' - 'for_each_dss_dev' + - 'for_each_early_section_nr' - 'for_each_efi_memory_desc' - 'for_each_efi_memory_desc_in_map' - 'for_each_element' @@ -403,7 +404,6 @@ ForEachMacros: - 'for_each_possible_cpu_wrap' - 'for_each_present_blessed_reg' - 'for_each_present_cpu' - - 'for_each_present_section_nr' - 'for_each_prime_number' - 'for_each_prime_number_from' - 'for_each_probe_cache_entry' diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 5eead3346f1e..b0338de2f1d8 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -972,7 +972,7 @@ void __init memory_dev_init(void) * block so that it can be covered. */ block_id = ULONG_MAX; - for_each_present_section_nr(0, nr) { + for_each_early_section_nr(0, nr) { if (block_id != ULONG_MAX && memory_block_id(nr) == block_id) continue; diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 5c052c08d9aa..3b96d6c7123b 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -2059,7 +2059,6 @@ static inline struct mem_section *__nr_to_section(unsigned long nr) * accommodate SECTION_MAP_LAST_BIT. We use BUILD_BUG_ON() to ensure this. */ enum { - SECTION_MARKED_PRESENT_BIT, SECTION_HAS_MEM_MAP_BIT, SECTION_IS_ONLINE_BIT, SECTION_IS_EARLY_BIT, @@ -2069,7 +2068,6 @@ enum { SECTION_MAP_LAST_BIT, }; -#define SECTION_MARKED_PRESENT BIT(SECTION_MARKED_PRESENT_BIT) #define SECTION_HAS_MEM_MAP BIT(SECTION_HAS_MEM_MAP_BIT) #define SECTION_IS_ONLINE BIT(SECTION_IS_ONLINE_BIT) #define SECTION_IS_EARLY BIT(SECTION_IS_EARLY_BIT) @@ -2086,16 +2084,6 @@ static inline struct page *__section_mem_map_addr(struct mem_section *section) return (struct page *)map; } -static inline int present_section(const struct mem_section *section) -{ - return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); -} - -static inline int present_section_nr(unsigned long nr) -{ - return present_section(__nr_to_section(nr)); -} - static inline int valid_section(const struct mem_section *section) { return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); @@ -2111,6 +2099,11 @@ static inline int valid_section_nr(unsigned long nr) return valid_section(__nr_to_section(nr)); } +static inline int early_section_nr(unsigned long nr) +{ + return early_section(__nr_to_section(nr)); +} + static inline int online_section(const struct mem_section *section) { return (section && (section->section_mem_map & SECTION_IS_ONLINE)); @@ -2300,20 +2293,20 @@ static inline unsigned long next_valid_pfn(unsigned long pfn, unsigned long end_ #endif -static inline unsigned long next_present_section_nr(unsigned long section_nr) +static inline unsigned long next_early_section_nr(unsigned long section_nr) { while (++section_nr <= __highest_used_section_nr) { - if (present_section_nr(section_nr)) + if (early_section_nr(section_nr)) return section_nr; } return -1; } -#define for_each_present_section_nr(start, section_nr) \ - for (section_nr = next_present_section_nr(start - 1); \ +#define for_each_early_section_nr(start, section_nr) \ + for (section_nr = next_early_section_nr(start - 1); \ section_nr != -1; \ - section_nr = next_present_section_nr(section_nr)) + section_nr = next_early_section_nr(section_nr)) /* * These are _only_ used during initialisation, therefore they diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index d5fd61c83bac..09376f5b1d92 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -903,7 +903,6 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, if (!section_vmemmap_optimizable(ms)) 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 */ diff --git a/mm/sparse.c b/mm/sparse.c index a0f50ca5acf5..5d2d9f95d402 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -170,13 +170,14 @@ static void __init mminit_validate_memmodel_limits(unsigned long *start_pfn, */ unsigned long __highest_used_section_nr; -static inline unsigned long first_present_section_nr(void) +static inline unsigned long first_early_section_nr(void) { - return next_present_section_nr(-1); + return next_early_section_nr(-1); } void __init sparse_sections_init(void) { + const unsigned long flags = SECTION_IS_EARLY | SECTION_IS_ONLINE; unsigned long pfn, start_pfn, end_pfn, section_nr; int i, nid; @@ -196,9 +197,7 @@ void __init sparse_sections_init(void) continue; set_section_nid(section_nr, nid); - ms->section_mem_map = sparse_encode_early_nid(nid) | - SECTION_IS_ONLINE; - __section_mark_present(ms, section_nr); + ms->section_mem_map = sparse_encode_early_nid(nid) | flags; } } __highest_used_section_nr = section_nr; @@ -230,7 +229,7 @@ static void __init sparse_metadata_init_nid(int nid, if (!usage) panic("Failed to allocate usemap for node %d\n", nid); - for_each_present_section_nr(start_section_nr, section_nr) { + for_each_early_section_nr(start_section_nr, section_nr) { const unsigned long pfn = section_nr_to_pfn(section_nr); struct page *mem_map; @@ -244,18 +243,18 @@ static void __init sparse_metadata_init_nid(int nid, section_nr); memmap_boot_pages_add(section_nr_vmemmap_pages(pfn, PAGES_PER_SECTION)); sparse_init_one_section(__nr_to_section(section_nr), section_nr, - mem_map, usage, SECTION_IS_EARLY); + mem_map, usage, 0); usage = (void *)usage + mem_section_usage_size(); } } static void __init sparse_metadata_init(void) { - unsigned long start_section_nr = first_present_section_nr(); + unsigned long start_section_nr = first_early_section_nr(); int nid_begin = sparse_early_nid(__nr_to_section(start_section_nr)); unsigned long section_nr, nr_sections = 1; - for_each_present_section_nr(start_section_nr + 1, section_nr) { + for_each_early_section_nr(start_section_nr + 1, section_nr) { const int nid = sparse_early_nid(__nr_to_section(section_nr)); if (nid == nid_begin) { diff --git a/mm/sparse.h b/mm/sparse.h index c396d5c05cfc..19664d702af8 100644 --- a/mm/sparse.h +++ b/mm/sparse.h @@ -42,12 +42,6 @@ static inline void sparse_init_one_section(struct mem_section *ms, ms->usage = usage; } -static inline void __section_mark_present(struct mem_section *ms, - unsigned long section_nr) -{ - ms->section_mem_map |= SECTION_MARKED_PRESENT; -} - static inline size_t mem_section_usage_size(void) { return struct_size_t(struct mem_section_usage, pageblock_flags,