[PATCH v2 10/10] mm/bootmem_info: remove CONFIG_HAVE_BOOTMEM_INFO_NODE
From: David Hildenbrand (Arm)
Date: Thu Jul 16 2026 - 11:07:46 EST
The whole infrastructure is unused now. Let's remove the config option
along with mm/bootmem_info. + include/linux/bootmem_info.h.
Reviewed-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Reviewed-by: Muchun Song <muchun.song@xxxxxxxxx>
Signed-off-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
---
MAINTAINERS | 1 -
include/linux/bootmem_info.h | 89 --------------------------------------------
mm/Kconfig | 7 ----
mm/Makefile | 1 -
mm/bootmem_info.c | 72 -----------------------------------
5 files changed, 170 deletions(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index d19822d574fd4..9a67ae0f7865e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16877,7 +16877,6 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock.git fixes
F: Documentation/core-api/boot-time-mm.rst
F: include/linux/kho/abi/memblock.h
F: include/linux/memblock.h
-F: mm/bootmem_info.c
F: mm/memblock.c
F: mm/memtest.c
F: mm/mm_init.c
diff --git a/include/linux/bootmem_info.h b/include/linux/bootmem_info.h
deleted file mode 100644
index 486acc6127039..0000000000000
--- a/include/linux/bootmem_info.h
+++ /dev/null
@@ -1,89 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __LINUX_BOOTMEM_INFO_H
-#define __LINUX_BOOTMEM_INFO_H
-
-#include <linux/mm.h>
-#include <linux/kmemleak.h>
-
-/*
- * Types for free bootmem stored in the low bits of page->private.
- */
-enum bootmem_type {
- MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE = 1,
- SECTION_INFO = MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE,
- MIX_SECTION_INFO,
- NODE_INFO,
- MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO,
-};
-
-#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
-void __init register_page_bootmem_info_node(struct pglist_data *pgdat);
-void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
- unsigned long nr_pages);
-
-void get_page_bootmem(unsigned long info, struct page *page,
- enum bootmem_type type);
-void put_page_bootmem(struct page *page);
-
-static inline enum bootmem_type bootmem_type(const struct page *page)
-{
- return (unsigned long)page->private & 0xf;
-}
-
-static inline unsigned long bootmem_info(const struct page *page)
-{
- return (unsigned long)page->private >> 4;
-}
-
-/*
- * Any memory allocated via the memblock allocator and not via the
- * buddy will be marked reserved already in the memmap. For those
- * pages, we can call this function to free it to buddy allocator.
- */
-static inline void free_bootmem_page(struct page *page)
-{
- enum bootmem_type type = bootmem_type(page);
-
- if (type == SECTION_INFO || type == MIX_SECTION_INFO) {
- VM_WARN_ON_PAGE(page_ref_count(page) != 2, page);
- put_page_bootmem(page);
- } else {
- free_reserved_page(page);
- }
-}
-#else
-static inline void register_page_bootmem_info_node(struct pglist_data *pgdat)
-{
-}
-
-static inline void register_page_bootmem_memmap(unsigned long section_nr,
- struct page *map, unsigned long nr_pages)
-{
-}
-
-static inline void put_page_bootmem(struct page *page)
-{
-}
-
-static inline enum bootmem_type bootmem_type(const struct page *page)
-{
- return SECTION_INFO;
-}
-
-static inline unsigned long bootmem_info(const struct page *page)
-{
- return 0;
-}
-
-static inline void get_page_bootmem(unsigned long info, struct page *page,
- enum bootmem_type type)
-{
-}
-
-static inline void free_bootmem_page(struct page *page)
-{
- free_reserved_page(page);
-}
-#endif
-
-#endif /* __LINUX_BOOTMEM_INFO_H */
diff --git a/mm/Kconfig b/mm/Kconfig
index 592003a258bad..169a3ba12a255 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -509,13 +509,6 @@ config EXCLUSIVE_SYSTEM_RAM
def_bool y
depends on !DEVMEM || STRICT_DEVMEM
-#
-# Only be set on architectures that have completely implemented memory hotplug
-# feature. If you are not sure, don't touch it.
-#
-config HAVE_BOOTMEM_INFO_NODE
- def_bool n
-
config ARCH_ENABLE_MEMORY_HOTPLUG
bool
diff --git a/mm/Makefile b/mm/Makefile
index 4fc713867b9bd..52428a3d3ae14 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -141,7 +141,6 @@ obj-$(CONFIG_MEMFD_CREATE) += memfd.o
obj-$(CONFIG_MAPPING_DIRTY_HELPERS) += mapping_dirty_helpers.o
obj-$(CONFIG_PTDUMP) += ptdump.o
obj-$(CONFIG_PAGE_REPORTING) += page_reporting.o
-obj-$(CONFIG_HAVE_BOOTMEM_INFO_NODE) += bootmem_info.o
obj-$(CONFIG_GENERIC_IOREMAP) += ioremap.o
obj-$(CONFIG_SHRINKER_DEBUG) += shrinker_debug.o
obj-$(CONFIG_EXECMEM) += execmem.o
diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c
deleted file mode 100644
index 0fa78db7fbc0b..0000000000000
--- a/mm/bootmem_info.c
+++ /dev/null
@@ -1,72 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Bootmem core functions.
- *
- * Copyright (c) 2020, Bytedance.
- *
- * Author: Muchun Song <songmuchun@xxxxxxxxxxxxx>
- *
- */
-#include <linux/mm.h>
-#include <linux/compiler.h>
-#include <linux/memblock.h>
-#include <linux/bootmem_info.h>
-#include <linux/memory_hotplug.h>
-#include <linux/kmemleak.h>
-
-void get_page_bootmem(unsigned long info, struct page *page,
- enum bootmem_type type)
-{
- BUG_ON(type > 0xf);
- BUG_ON(info > (ULONG_MAX >> 4));
- set_page_private(page, info << 4 | type);
- page_ref_inc(page);
-}
-
-void put_page_bootmem(struct page *page)
-{
- enum bootmem_type type = bootmem_type(page);
-
- BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE ||
- type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE);
-
- if (page_ref_dec_return(page) == 1) {
- set_page_private(page, 0);
- free_reserved_page(page);
- }
-}
-
-static void __init register_page_bootmem_info_section(unsigned long start_pfn)
-{
- unsigned long section_nr;
- struct mem_section *ms;
-
- start_pfn = SECTION_ALIGN_DOWN(start_pfn);
- section_nr = pfn_to_section_nr(start_pfn);
- ms = __nr_to_section(section_nr);
-
- if (!preinited_vmemmap_section(ms))
- register_page_bootmem_memmap(section_nr, pfn_to_page(start_pfn),
- PAGES_PER_SECTION);
-}
-
-void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
-{
- unsigned long pfn, end_pfn;
- int node = pgdat->node_id;
-
- pfn = pgdat->node_start_pfn;
- end_pfn = pgdat_end_pfn(pgdat);
-
- /* register section info */
- for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
- /*
- * Some platforms can assign the same pfn to multiple nodes - on
- * node0 as well as nodeN. To avoid registering a pfn against
- * multiple nodes we check that this pfn does not already
- * reside in some other nodes.
- */
- if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node))
- register_page_bootmem_info_section(pfn);
- }
-}
--
2.43.0