The patch titled
Subject: arch, mm: make releasing of memory to page allocator more explicit
has been added to the -mm mm-unstable branch. Its filename is
arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
Subject: arch, mm: make releasing of memory to page allocator more explicit
Date: Thu, 13 Mar 2025 15:50:03 +0200
The point where the memory is released from memblock to the buddy
allocator is hidden inside arch-specific mem_init()s and the call to
memblock_free_all() is needlessly duplicated in every artiste cure and
after introduction of arch_mm_preinit() hook, mem_init() implementation on
many architecture only contains the call to memblock_free_all().
Pull memblock_free_all() call into mm_core_init() and drop mem_init() on
relevant architectures to make it more explicit where the free memory is
released from memblock to the buddy allocator and to reduce code
duplication in architecture specific code.
Link: https://lkml.kernel.org/r/20250313135003.836600-14-rppt@xxxxxxxxxx
Signed-off-by: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> [x86]
Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> [m68k]
Tested-by: Mark Brown <broonie@xxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Andreas Larsson <andreas@xxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Borislav Betkov <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Cc: Guo Ren (csky) <guoren@xxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Cc: Madhavan Srinivasan <maddy@xxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Michal Simek <monstr@xxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Russel King <linux@xxxxxxxxxxxxxxx>
Cc: Stafford Horne <shorne@xxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Thomas Gleinxer <tglx@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Vineet Gupta <vgupta@xxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/alpha/mm/init.c | 6 ------
arch/arc/mm/init.c | 11 -----------
arch/arm/mm/init.c | 11 -----------
arch/arm64/mm/init.c | 11 -----------
arch/csky/mm/init.c | 5 -----
arch/hexagon/mm/init.c | 18 ------------------
arch/loongarch/kernel/numa.c | 5 -----
arch/loongarch/mm/init.c | 5 -----
arch/m68k/mm/init.c | 2 --
arch/microblaze/mm/init.c | 3 ---
arch/mips/mm/init.c | 5 -----
arch/nios2/mm/init.c | 6 ------
arch/openrisc/mm/init.c | 3 ---
arch/parisc/mm/init.c | 2 --
arch/powerpc/mm/mem.c | 5 -----
arch/riscv/mm/init.c | 5 -----
arch/s390/mm/init.c | 6 ------
arch/sh/mm/init.c | 2 --
arch/sparc/mm/init_32.c | 5 -----
arch/sparc/mm/init_64.c | 2 --
arch/um/kernel/mem.c | 2 --
arch/x86/mm/init_32.c | 3 ---
arch/x86/mm/init_64.c | 2 --
arch/xtensa/mm/init.c | 9 ---------
include/linux/memblock.h | 1 -
mm/internal.h | 3 ++-
mm/mm_init.c | 5 +++++
27 files changed, 7 insertions(+), 136 deletions(-)
--- a/arch/alpha/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/alpha/mm/init.c
@@ -273,12 +273,6 @@ srm_paging_stop (void)
}
#endif
-void __init
-mem_init(void)
-{
- memblock_free_all();
-}
-
static const pgprot_t protection_map[16] = {
[VM_NONE] = _PAGE_P(_PAGE_FOE | _PAGE_FOW |
_PAGE_FOR),
--- a/arch/arc/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/arc/mm/init.c
@@ -169,17 +169,6 @@ void __init arch_mm_preinit(void)
BUILD_BUG_ON((PTRS_PER_PTE * sizeof(pte_t)) > PAGE_SIZE);
}
-/*
- * mem_init - initializes memory
- *
- * Frees up bootmem
- * Calculates and displays memory available/used
- */
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
#ifdef CONFIG_HIGHMEM
int pfn_valid(unsigned long pfn)
{
--- a/arch/arm64/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/arm64/mm/init.c
@@ -406,17 +406,6 @@ void __init arch_mm_preinit(void)
}
}
-/*
- * mem_init() marks the free areas in the mem_map and tells us how much memory
- * is free. This is done after various parts of the system have claimed their
- * memory after the kernel image.
- */
-void __init mem_init(void)
-{
- /* this will put all unused low memory onto the freelists */
- memblock_free_all();
-}
-
void free_initmem(void)
{
void *lm_init_begin = lm_alias(__init_begin);
--- a/arch/arm/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/arm/mm/init.c
@@ -263,17 +263,6 @@ void __init arch_mm_preinit(void)
#endif
}
-/*
- * mem_init() marks the free areas in the mem_map and tells us how much
- * memory is free. This is done after various parts of the system have
- * claimed their memory after the kernel image.
- */
-void __init mem_init(void)
-{
- /* this will put all unused low memory onto the freelists */
- memblock_free_all();
-}
-
#ifdef CONFIG_STRICT_KERNEL_RWX
struct section_perm {
const char *name;
--- a/arch/csky/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/csky/mm/init.c
@@ -42,11 +42,6 @@ unsigned long empty_zero_page[PAGE_SIZE
__page_aligned_bss;
EXPORT_SYMBOL(empty_zero_page);
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
void free_initmem(void)
{
free_initmem_default(-1);
--- a/arch/hexagon/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/hexagon/mm/init.c
@@ -43,24 +43,6 @@ DEFINE_SPINLOCK(kmap_gen_lock);
/* checkpatch says don't init this to 0. */
unsigned long long kmap_generation;
-/*
- * mem_init - initializes memory
- *
- * Frees up bootmem
- * Fixes up more stuff for HIGHMEM
- * Calculates and displays memory available/used
- */
-void __init mem_init(void)
-{
- /* No idea where this is actually declared. Seems to evade LXR. */
- memblock_free_all();
-
- /*
- * To-Do: someone somewhere should wipe out the bootmem map
- * after we're done?
- */
-}
-
void sync_icache_dcache(pte_t pte)
{
unsigned long addr;
--- a/arch/loongarch/kernel/numa.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/loongarch/kernel/numa.c
@@ -387,11 +387,6 @@ void __init paging_init(void)
free_area_init(zones_size);
}
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
int pcibus_to_node(struct pci_bus *bus)
{
return dev_to_node(&bus->dev);
--- a/arch/loongarch/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/loongarch/mm/init.c
@@ -75,11 +75,6 @@ void __init paging_init(void)
free_area_init(max_zone_pfns);
}
-
-void __init mem_init(void)
-{
- memblock_free_all();
-}
#endif /* !CONFIG_NUMA */
void __ref free_initmem(void)
--- a/arch/m68k/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/m68k/mm/init.c
@@ -121,7 +121,5 @@ static inline void init_pointer_tables(v
void __init mem_init(void)
{
- /* this will put all memory onto the freelists */
- memblock_free_all();
init_pointer_tables();
}
--- a/arch/microblaze/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/microblaze/mm/init.c
@@ -107,9 +107,6 @@ void __init setup_memory(void)
void __init mem_init(void)
{
- /* this will put all memory onto the freelists */
- memblock_free_all();
-
mem_init_done = 1;
}
--- a/arch/mips/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/mips/mm/init.c
@@ -451,11 +451,6 @@ void __init arch_mm_preinit(void)
}
#endif /* !CONFIG_NUMA */
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
void free_init_pages(const char *what, unsigned long begin, unsigned long end)
{
unsigned long pfn;
--- a/arch/nios2/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/nios2/mm/init.c
@@ -60,12 +60,6 @@ void __init paging_init(void)
(unsigned long)empty_zero_page + PAGE_SIZE);
}
-void __init mem_init(void)
-{
- /* this will put all memory onto the freelists */
- memblock_free_all();
-}
-
void __init mmu_init(void)
{
flush_tlb_all();
--- a/arch/openrisc/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/openrisc/mm/init.c
@@ -196,9 +196,6 @@ void __init mem_init(void)
/* clear the zero-page */
memset((void *)empty_zero_page, 0, PAGE_SIZE);
- /* this will put all low memory onto the freelists */
- memblock_free_all();
-
printk("mem_init_done ...........................................\n");
mem_init_done = 1;
return;
--- a/arch/parisc/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/parisc/mm/init.c
@@ -562,8 +562,6 @@ void __init mem_init(void)
BUILD_BUG_ON(TMPALIAS_MAP_START >= 0x80000000);
#endif
- memblock_free_all();
-
#ifdef CONFIG_PA11
if (boot_cpu_data.cpu_type == pcxl2 || boot_cpu_data.cpu_type == pcxl) {
pcxl_dma_start = (unsigned long)SET_MAP_OFFSET(MAP_START);
--- a/arch/powerpc/mm/mem.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/powerpc/mm/mem.c
@@ -327,11 +327,6 @@ void __init arch_mm_preinit(void)
#endif /* CONFIG_PPC32 */
}
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
void free_initmem(void)
{
ppc_md.progress = ppc_printk_progress;
--- a/arch/riscv/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/riscv/mm/init.c
@@ -196,11 +196,6 @@ void __init arch_mm_preinit(void)
print_vm_layout();
}
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
/* Limit the memory size via mem. */
static phys_addr_t memory_limit;
#ifdef CONFIG_XIP_KERNEL
--- a/arch/s390/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/s390/mm/init.c
@@ -165,12 +165,6 @@ void __init arch_mm_preinit(void)
setup_zero_pages(); /* Setup zeroed pages. */
}
-void __init mem_init(void)
-{
- /* this will put all low memory onto the freelists */
- memblock_free_all();
-}
-
unsigned long memory_block_size_bytes(void)
{
/*
--- a/arch/sh/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/sh/mm/init.c
@@ -330,8 +330,6 @@ unsigned int mem_init_done = 0;
void __init mem_init(void)
{
- memblock_free_all();
-
/* Set this up early, so we can take care of the zero page */
cpu_cache_init();
--- a/arch/sparc/mm/init_32.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/sparc/mm/init_32.c
@@ -264,11 +264,6 @@ void __init arch_mm_preinit(void)
taint_real_pages();
}
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
void sparc_flush_page_to_ram(struct page *page)
{
unsigned long vaddr = (unsigned long)page_address(page);
--- a/arch/sparc/mm/init_64.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/sparc/mm/init_64.c
@@ -2505,8 +2505,6 @@ static void __init register_page_bootmem
}
void __init mem_init(void)
{
- memblock_free_all();
-
/*
* Must be done after boot memory is put on freelist, because here we
* might set fields in deferred struct pages that have not yet been
--- a/arch/um/kernel/mem.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/um/kernel/mem.c
@@ -71,8 +71,6 @@ void __init arch_mm_preinit(void)
void __init mem_init(void)
{
- /* this will put all low memory onto the freelists */
- memblock_free_all();
kmalloc_ok = 1;
}
--- a/arch/x86/mm/init_32.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/x86/mm/init_32.c
@@ -702,9 +702,6 @@ void __init arch_mm_preinit(void)
void __init mem_init(void)
{
- /* this will put all low memory onto the freelists */
- memblock_free_all();
-
after_bootmem = 1;
x86_init.hyper.init_after_bootmem();
--- a/arch/x86/mm/init_64.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/x86/mm/init_64.c
@@ -1368,8 +1368,6 @@ void __init mem_init(void)
{
/* clear_bss() already clear the empty_zero_page */
- /* this will put all memory onto the freelists */
- memblock_free_all();
after_bootmem = 1;
x86_init.hyper.init_after_bootmem();
--- a/arch/xtensa/mm/init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/arch/xtensa/mm/init.c
@@ -129,15 +129,6 @@ void __init zones_init(void)
print_vm_layout();
}
-/*
- * Initialize memory pages.
- */
-
-void __init mem_init(void)
-{
- memblock_free_all();
-}
-
static void __init parse_memmap_one(char *p)
{
char *oldp;
--- a/include/linux/memblock.h~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/include/linux/memblock.h
@@ -133,7 +133,6 @@ int memblock_mark_nomap(phys_addr_t base
int memblock_clear_nomap(phys_addr_t base, phys_addr_t size);
int memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t size);
-void memblock_free_all(void);
void memblock_free(void *ptr, size_t size);
void reset_all_zones_managed_pages(void);
--- a/mm/internal.h~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/mm/internal.h
@@ -1475,7 +1475,8 @@ static inline bool gup_must_unshare(stru
}
extern bool mirrored_kernelcore;
-extern bool memblock_has_mirror(void);
+bool memblock_has_mirror(void);
+void memblock_free_all(void);
static __always_inline void vma_set_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end,
--- a/mm/mm_init.c~arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit
+++ a/mm/mm_init.c
@@ -2738,6 +2738,10 @@ void __init __weak arch_mm_preinit(void)
{
}
+void __init __weak mem_init(void)
+{
+}
+
/*
* Set up kernel memory allocators
*/
@@ -2761,6 +2765,7 @@ void __init mm_core_init(void)
report_meminit();
kmsan_init_shadow();
stack_depot_early_init();
+ memblock_free_all();
mem_init();
kmem_cache_init();
/*
_
Patches currently in -mm which might be from rppt@xxxxxxxxxx are
arm-mem_init-use-memblock_phys_free-to-free-dma-memory-on-sa1111.patch
csky-move-setup_initrd-to-setupc.patch
hexagon-move-initialization-of-init_mmcontext-init-to-paging_init.patch
mips-consolidate-mem_init-for-numa-machines.patch
mips-make-setup_zero_pages-use-memblock.patch
nios2-move-pr_debug-about-memory-start-and-end-to-setup_arch.patch
s390-make-setup_zero_pages-use-memblock.patch
xtensa-split-out-printing-of-virtual-memory-layout-to-a-function.patch
arch-mm-set-max_mapnr-when-allocating-memory-map-for-flatmem.patch
arch-mm-set-high_memory-in-free_area_init.patch
arch-mm-streamline-highmem-freeing.patch
arch-mm-introduce-arch_mm_preinit.patch
arch-mm-make-releasing-of-memory-to-page-allocator-more-explicit.patch
