Re: [PATCH 10/12] mm: Remove devmap related functions and page table bits

Jason Gunthorpe
2025-06-03T13:50:20Z

On Thu, May 29, 2025 at 04:32:11PM +1000, Alistair Popple wrote:
> Now that DAX and all other reference counts to ZONE_DEVICE pages are
> managed normally there is no need for the special devmap PTE/PMD/PUD
> page table bits. So drop all references to these, freeing up a
> software defined page table bit on architectures supporting it.
>
> Signed-off-by: Alistair Popple <apopple@nvidia.com>
> Acked-by: Will Deacon <will@kernel.org> # arm64
> Suggested-by: Chunyan Zhang <zhang.lyra@gmail.com>
> Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
> ---
> Documentation/mm/arch_pgtable_helpers.rst | 6 +--
> arch/arm64/Kconfig | 1 +-
> arch/arm64/include/asm/pgtable-prot.h | 1 +-
> arch/arm64/include/asm/pgtable.h | 24 +--------
> arch/loongarch/Kconfig | 1 +-
> arch/loongarch/include/asm/pgtable-bits.h | 6 +--
> arch/loongarch/include/asm/pgtable.h | 19 +------
> arch/powerpc/Kconfig | 1 +-
> arch/powerpc/include/asm/book3s/64/hash-4k.h | 6 +--
> arch/powerpc/include/asm/book3s/64/hash-64k.h | 7 +--
> arch/powerpc/include/asm/book3s/64/pgtable.h | 53 +------------------
> arch/powerpc/include/asm/book3s/64/radix.h | 14 +-----
> arch/riscv/Kconfig | 1 +-
> arch/riscv/include/asm/pgtable-64.h | 20 +-------
> arch/riscv/include/asm/pgtable-bits.h | 1 +-
> arch/riscv/include/asm/pgtable.h | 17 +------
> arch/x86/Kconfig | 1 +-
> arch/x86/include/asm/pgtable.h | 51 +-----------------
> arch/x86/include/asm/pgtable_types.h | 5 +--
> include/linux/mm.h | 7 +--
> include/linux/pgtable.h | 19 +------
> mm/Kconfig | 4 +-
> mm/debug_vm_pgtable.c | 59 +--------------------
> mm/hmm.c | 3 +-
> mm/madvise.c | 8 +--
> 25 files changed, 17 insertions(+), 318 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason