[PATCH v3 0/4] arch, mm: consolidate empty_zero_page

Mike Rapoport
2026-02-11T10:31:58Z

From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>

Hi,

These patches cleanup handling of ZERO_PAGE() and zero_pfn.

v3 changes:
* move zero_page_pfn extern declaration back inside the helpers
* add tags, thanks all!

v2: https://lore.kernel.org/all/20260209144058.2092871-1-rppt@kernel.org
* add patches that cleanup zero_pfn code a bit (patches 1,2)
* add a patch that caches struct page for empty_zero_page (patch 4)
* use uint8_t instead of unsigned long for empty_zero_page
* fix sparc64 changes in patch 3

v1: https://lore.kernel.org/all/20260124095628.668870-1-rppt@kernel.org

Mike Rapoport (Microsoft) (4):
mm: don't special case !MMU for is_zero_pfn() and my_zero_pfn()
mm: rename my_zero_pfn() to zero_pfn()
arch, mm: consolidate empty_zero_page
mm: cache struct page for empty_zero_page and return it from ZERO_PAGE()

arch/alpha/include/asm/pgtable.h | 6 ---
arch/arc/include/asm/pgtable.h | 3 --
arch/arc/mm/init.c | 2 -
arch/arm/include/asm/pgtable.h | 9 -----
arch/arm/mm/mmu.c | 7 ----
arch/arm/mm/nommu.c | 7 ----
arch/arm64/include/asm/pgtable.h | 7 ----
arch/arm64/mm/init.c | 5 +++
arch/arm64/mm/mmu.c | 7 ----
arch/csky/include/asm/pgtable.h | 3 --
arch/csky/mm/init.c | 3 --
arch/hexagon/include/asm/pgtable.h | 6 ---
arch/hexagon/kernel/head.S | 5 ---
arch/hexagon/kernel/hexagon_ksyms.c | 1 -
arch/loongarch/include/asm/pgtable.h | 9 -----
arch/loongarch/mm/init.c | 3 --
arch/m68k/include/asm/pgtable_mm.h | 9 -----
arch/m68k/include/asm/pgtable_no.h | 7 ----
arch/m68k/mm/init.c | 9 -----
arch/m68k/mm/mcfmmu.c | 2 -
arch/m68k/mm/motorola.c | 6 ---
arch/m68k/mm/sun3mmu.c | 2 -
arch/microblaze/include/asm/pgtable.h | 10 -----
arch/microblaze/kernel/head.S | 4 --
arch/microblaze/kernel/microblaze_ksyms.c | 2 -
arch/mips/mm/init.c | 11 +-----
arch/nios2/include/asm/pgtable.h | 7 ----
arch/nios2/kernel/head.S | 10 -----
arch/nios2/kernel/nios2_ksyms.c | 1 -
arch/openrisc/include/asm/pgtable.h | 4 --
arch/openrisc/kernel/head.S | 3 --
arch/openrisc/kernel/or32_ksyms.c | 1 -
arch/openrisc/mm/init.c | 3 --
arch/parisc/include/asm/pgtable.h | 11 ------
arch/parisc/mm/init.c | 6 ---
arch/powerpc/include/asm/pgtable.h | 6 ---
arch/powerpc/mm/mem.c | 3 --
arch/riscv/include/asm/pgtable.h | 7 ----
arch/riscv/mm/init.c | 4 --
arch/s390/mm/init.c | 4 +-
arch/sh/include/asm/pgtable.h | 8 ----
arch/sh/include/asm/setup.h | 3 +-
arch/sh/kernel/head_32.S | 4 +-
arch/sh/kernel/sh_ksyms_32.c | 1 -
arch/sh/mm/init.c | 1 -
arch/sparc/include/asm/pgtable_32.h | 8 ----
arch/sparc/include/asm/pgtable_64.h | 3 --
arch/sparc/include/asm/setup.h | 2 -
arch/sparc/kernel/head_32.S | 7 ----
arch/sparc/mm/init_32.c | 4 --
arch/sparc/mm/init_64.c | 24 +++++-------
arch/um/include/asm/pgtable.h | 9 -----
arch/um/include/shared/kern_util.h | 1 -
arch/um/kernel/mem.c | 16 --------
arch/um/kernel/um_arch.c | 1 -
arch/x86/include/asm/pgtable.h | 8 ----
arch/x86/kernel/head_32.S | 4 --
arch/x86/kernel/head_64.S | 7 ----
arch/x86/kvm/mmu/spte.h | 2 +-
arch/xtensa/include/asm/pgtable.h | 4 --
arch/xtensa/kernel/head.S | 3 --
arch/xtensa/kernel/xtensa_ksyms.c | 2 -
fs/dax.c | 2 +-
fs/proc/vmcore.c | 2 +-
include/linux/pgtable.h | 48 ++++++++++++++---------
mm/huge_memory.c | 2 +-
mm/memory.c | 15 +------
mm/migrate.c | 2 +-
mm/mm_init.c | 28 +++++++++++++
mm/userfaultfd.c | 4 +-
70 files changed, 86 insertions(+), 354 deletions(-)

base-commit: 50c7f34c5c7403a12003c6759f6f6ca9a5a10872
--
2.51.0

*** BLURB HERE ***

Mike Rapoport (Microsoft) (4):
mm: don't special case !MMU for is_zero_pfn() and my_zero_pfn()
mm: rename my_zero_pfn() to zero_pfn()
arch, mm: consolidate empty_zero_page
mm: cache struct page for empty_zero_page and return it from
ZERO_PAGE()

arch/alpha/include/asm/pgtable.h | 6 ---
arch/arc/include/asm/pgtable.h | 3 --
arch/arc/mm/init.c | 2 -
arch/arm/include/asm/pgtable.h | 9 ----
arch/arm/mm/mmu.c | 7 ----
arch/arm/mm/nommu.c | 7 ----
arch/arm64/include/asm/pgtable.h | 7 ----
arch/arm64/mm/init.c | 5 +++
arch/arm64/mm/mmu.c | 7 ----
arch/csky/include/asm/pgtable.h | 3 --
arch/csky/mm/init.c | 3 --
arch/hexagon/include/asm/pgtable.h | 6 ---
arch/hexagon/kernel/head.S | 5 ---
arch/hexagon/kernel/hexagon_ksyms.c | 1 -
arch/loongarch/include/asm/pgtable.h | 9 ----
arch/loongarch/mm/init.c | 3 --
arch/m68k/include/asm/pgtable_mm.h | 9 ----
arch/m68k/include/asm/pgtable_no.h | 7 ----
arch/m68k/mm/init.c | 9 ----
arch/m68k/mm/mcfmmu.c | 2 -
arch/m68k/mm/motorola.c | 6 ---
arch/m68k/mm/sun3mmu.c | 2 -
arch/microblaze/include/asm/pgtable.h | 10 -----
arch/microblaze/kernel/head.S | 4 --
arch/microblaze/kernel/microblaze_ksyms.c | 2 -
arch/mips/mm/init.c | 11 +----
arch/nios2/include/asm/pgtable.h | 7 ----
arch/nios2/kernel/head.S | 10 -----
arch/nios2/kernel/nios2_ksyms.c | 1 -
arch/openrisc/include/asm/pgtable.h | 4 --
arch/openrisc/kernel/head.S | 3 --
arch/openrisc/kernel/or32_ksyms.c | 1 -
arch/openrisc/mm/init.c | 3 --
arch/parisc/include/asm/pgtable.h | 11 -----
arch/parisc/mm/init.c | 6 ---
arch/powerpc/include/asm/pgtable.h | 6 ---
arch/powerpc/mm/mem.c | 3 --
arch/riscv/include/asm/pgtable.h | 7 ----
arch/riscv/mm/init.c | 4 --
arch/s390/mm/init.c | 4 +-
arch/sh/include/asm/pgtable.h | 8 ----
arch/sh/include/asm/setup.h | 3 +-
arch/sh/kernel/head_32.S | 4 +-
arch/sh/kernel/sh_ksyms_32.c | 1 -
arch/sh/mm/init.c | 1 -
arch/sparc/include/asm/pgtable_32.h | 8 ----
arch/sparc/include/asm/pgtable_64.h | 3 --
arch/sparc/include/asm/setup.h | 2 -
arch/sparc/kernel/head_32.S | 7 ----
arch/sparc/mm/init_32.c | 4 --
arch/sparc/mm/init_64.c | 24 ++++-------
arch/um/include/asm/pgtable.h | 9 ----
arch/um/include/shared/kern_util.h | 1 -
arch/um/kernel/mem.c | 16 -------
arch/um/kernel/um_arch.c | 1 -
arch/x86/include/asm/pgtable.h | 8 ----
arch/x86/kernel/head_32.S | 4 --
arch/x86/kernel/head_64.S | 7 ----
arch/x86/kvm/mmu/spte.h | 2 +-
arch/xtensa/include/asm/pgtable.h | 4 --
arch/xtensa/kernel/head.S | 3 --
arch/xtensa/kernel/xtensa_ksyms.c | 2 -
fs/dax.c | 2 +-
fs/proc/vmcore.c | 2 +-
include/linux/pgtable.h | 51 +++++++++++++++--------
mm/huge_memory.c | 2 +-
mm/memory.c | 15 +------
mm/migrate.c | 2 +-
mm/mm_init.c | 28 +++++++++++++
mm/userfaultfd.c | 4 +-
70 files changed, 89 insertions(+), 354 deletions(-)

base-commit: 50c7f34c5c7403a12003c6759f6f6ca9a5a10872
--
2.51.0