[PATCH v2 06/15] mm/sparse: remove !CONFIG_SPARSEMEM_VMEMMAP leftovers for CONFIG_MEMORY_HOTPLUG
David Hildenbrand (Arm)
david at kernel.org
Fri Mar 20 15:13:38 PDT 2026
CONFIG_MEMORY_HOTPLUG now depends on CONFIG_SPARSEMEM_VMEMMAP. So
let's remove the !CONFIG_SPARSEMEM_VMEMMAP leftovers that are dead code.
Adjust the comment above fill_subsection_map() accordingly.
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs at kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt at kernel.org>
Signed-off-by: David Hildenbrand (Arm) <david at kernel.org>
---
mm/sparse.c | 69 ++-----------------------------------------------------------
1 file changed, 2 insertions(+), 67 deletions(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index 93252112860e..875f718a4c79 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -657,7 +657,6 @@ void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
}
}
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
static struct page * __meminit populate_section_memmap(unsigned long pfn,
unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
struct dev_pagemap *pgmap)
@@ -729,73 +728,11 @@ static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
return rc;
}
-#else
-static struct page * __meminit populate_section_memmap(unsigned long pfn,
- unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
- struct dev_pagemap *pgmap)
-{
- return kvmalloc_node(array_size(sizeof(struct page),
- PAGES_PER_SECTION), GFP_KERNEL, nid);
-}
-
-static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
- struct vmem_altmap *altmap)
-{
- kvfree(pfn_to_page(pfn));
-}
-
-static void free_map_bootmem(struct page *memmap)
-{
- unsigned long maps_section_nr, removing_section_nr, i;
- unsigned long type, nr_pages;
- struct page *page = virt_to_page(memmap);
-
- nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
- >> PAGE_SHIFT;
-
- for (i = 0; i < nr_pages; i++, page++) {
- type = bootmem_type(page);
-
- BUG_ON(type == NODE_INFO);
-
- maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
- removing_section_nr = bootmem_info(page);
-
- /*
- * When this function is called, the removing section is
- * logical offlined state. This means all pages are isolated
- * from page allocator. If removing section's memmap is placed
- * on the same section, it must not be freed.
- * If it is freed, page allocator may allocate it which will
- * be removed physically soon.
- */
- if (maps_section_nr != removing_section_nr)
- put_page_bootmem(page);
- }
-}
-
-static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
-{
- return 0;
-}
-
-static bool is_subsection_map_empty(struct mem_section *ms)
-{
- return true;
-}
-
-static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
-{
- return 0;
-}
-#endif /* CONFIG_SPARSEMEM_VMEMMAP */
/*
- * To deactivate a memory region, there are 3 cases to handle across
- * two configurations (SPARSEMEM_VMEMMAP={y,n}):
+ * To deactivate a memory region, there are 3 cases to handle:
*
- * 1. deactivation of a partial hot-added section (only possible in
- * the SPARSEMEM_VMEMMAP=y case).
+ * 1. deactivation of a partial hot-added section:
* a) section was present at memory init.
* b) section was hot-added post memory init.
* 2. deactivation of a complete hot-added section.
@@ -803,8 +740,6 @@ static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
*
* For 1, when subsection_map does not empty we will not be freeing the
* usage map, but still need to free the vmemmap range.
- *
- * For 2 and 3, the SPARSEMEM_VMEMMAP={y,n} cases are unified
*/
static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
struct vmem_altmap *altmap)
--
2.43.0
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