[PATCH 09/12] mm/sparse: remove SECTION_MARKED_PRESENT
From: "David Hildenbrand (Arm)" <david@kernel.org>
Date: 2026-09-09 13:35:18
Also in:
linux-cxl, linux-fsdevel, linux-mm, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, gdb kernel debugging helper scripts, memory hot(un)plug, memory management, memory management - core, memory management - mglru (multi-gen lru), the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Jan Kiszka, Kieran Bingham, David Hildenbrand, Oscar Salvador, Andrew Morton, Linus Torvalds
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_prepare_early_sections(). Get rid of SECTION_MARKED_PRESENT entirely and rename for_each_present_section_nr() to for_each_early_section_nr(). Also update the gdb script to use the updated value for SECTION_IS_EARLY. No functional change intended. Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> --- drivers/base/memory.c | 2 +- include/linux/mmzone.h | 27 ++++++++++----------------- mm/sparse-vmemmap.c | 1 - mm/sparse.c | 17 ++++++++--------- mm/sparse.h | 6 ------ scripts/gdb/linux/mm.py | 2 +- 6 files changed, 20 insertions(+), 35 deletions(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 5eead3346f1e3..b0338de2f1d82 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 e0fac344f6ac2..62cff59dd80c4 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h@@ -2084,7 +2084,6 @@ 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,
@@ -2094,7 +2093,6 @@ 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)
@@ -2111,16 +2109,6 @@ 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));
@@ -2136,6 +2124,11 @@ 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));
@@ -2315,20 +2308,20 @@ 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 e62e6aa07f126..5aba058df6b67 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c@@ -890,7 +890,6 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn, page_init_poison(memmap, sizeof(struct page) * nr_pages); ms = __nr_to_section(section_nr); - __section_mark_present(ms, 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 2d0f2db34f4cf..344acaaed94db 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;
@@ -231,7 +230,7 @@ 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) { unsigned long pfn = section_nr_to_pfn(section_nr); struct page *mem_map;
@@ -246,18 +245,18 @@ static void __init sparse_metadata_init_nid(int nid, memmap_boot_pages_add(section_nr_vmemmap_pages(pfn, PAGES_PER_SECTION, NULL, NULL)); 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 a3af4967fd5c5..03351f2467e34 100644
--- a/mm/sparse.h
+++ b/mm/sparse.h@@ -114,12 +114,6 @@ 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,
diff --git a/scripts/gdb/linux/mm.py b/scripts/gdb/linux/mm.py
index 193a88d763abf..73d637d28c8e6 100644
--- a/scripts/gdb/linux/mm.py
+++ b/scripts/gdb/linux/mm.py@@ -76,7 +76,7 @@ class x86_page_ops(): self.SECTION_IS_EARLY = 1 << int(gdb.parse_and_eval('SECTION_IS_EARLY_BIT')) except: self.SECTION_HAS_MEM_MAP = 1 << 0 - self.SECTION_IS_EARLY = 1 << 3 + self.SECTION_IS_EARLY = 1 << 2 self.SUBSECTION_SHIFT = 21 self.PAGES_PER_SUBSECTION = 1 << (self.SUBSECTION_SHIFT - self.PAGE_SHIFT)
--
2.43.0