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

From: Mike Rapoport <rppt@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Larsson <andreas@gaisler.com>,
	Borislav Petkov <bp@alien8.de>, Brian Cain <bcain@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	"Christophe Leroy (CS GROUP)" <chleroy@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	David Hildenbrand <david@kernel.org>,
	Dinh Nguyen <dinguyen@kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Guo Ren <guoren@kernel.org>, Helge Deller <deller@gmx.de>,
	Huacai Chen <chenhuacai@kernel.org>,
	Ingo Molnar <mingo@redhat.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
	"Liam R. Howlett" <Liam.Howlett@oracle.com>,
	Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
	Madhavan Srinivasan <maddy@linux.ibm.com>,
	Magnus Lindholm <linmag7@gmail.com>,
	Matt Turner <mattst88@gmail.com>,
	Max Filippov <jcmvbkbc@gmail.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Michal Hocko <mhocko@suse.com>, Michal Simek <monstr@monstr.eu>,
	Mike Rapoport <rppt@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Richard Weinberger <richard@nod.at>,
	Russell King <linux@armlinux.org.uk>,
	Stafford Horne <shorne@gmail.com>,
	Suren Baghdasaryan <surenb@google.com>,
	Thomas Gleixner <tglx@kernel.org>,
	Vineet Gupta <vgupta@kernel.org>,
	Vlastimil Babka <vbabka@suse.cz>, Will Deacon <will@kernel.org>,
	linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-snps-arc@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org,
	linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev,
	linux-m68k@lists.linux-m68k.org, linux-openrisc@vger.kernel.org,
	linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org,
	sparclinux@vger.kernel.org, linux-um@lists.infradead.org,
	linux-mm@kvack.org, x86@kernel.org
Subject: [PATCH v3 0/4] arch, mm: consolidate empty_zero_page
Date: Wed, 11 Feb 2026 12:31:37 +0200	[thread overview]
Message-ID: <20260211103141.3215197-1-rppt@kernel.org> (raw)

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