Re: [PATCH V12 1/5] mm: softdirty: Add pgtable_supports_soft_dirty()

[David Hildenbrand <david@redhat.com>]

On 15.09.25 12:13, Chunyan Zhang wrote:
> Some platforms can customize the PTE PMD entry soft-dirty bit making it
> unavailable even if the architecture provides the resource.
> 
> Add an API which architectures can define their specific implementations
> to detect if soft-dirty bit is available on which device the kernel is
> running.

You should probably mention that we are removing "ifdef 
CONFIG_MEM_SOFT_DIRTY" in favor of pgtable_supports_soft_dirty() checks 
that defaults to IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) if not overriden by 
the arch -> no change in behavior expected.

Then you should mention that we make sure to never set VM_SOFTDIRTY if 
!pgtable_supports_soft_dirty(), so we will never run into VM_SOFTDIRTY 
checks.

> 
> Signed-off-by: Chunyan Zhang <zhangchunyan@iscas.ac.cn>
> ---
>   fs/proc/task_mmu.c      | 15 ++++++---------
>   include/linux/mm.h      |  3 +++
>   include/linux/pgtable.h | 12 ++++++++++++
>   mm/debug_vm_pgtable.c   | 10 +++++-----
>   mm/huge_memory.c        | 13 +++++++------
>   mm/internal.h           |  2 +-
>   mm/mmap.c               |  6 ++++--
>   mm/mremap.c             | 13 +++++++------
>   mm/userfaultfd.c        | 10 ++++------
>   mm/vma.c                |  6 ++++--
>   mm/vma_exec.c           |  5 ++++-
>   11 files changed, 57 insertions(+), 38 deletions(-)
> 

Good! All relevant CONFIG_MEM_SOFT_DIRTY occurrences seem to be gone 
now, which is nice.

Nothing jumped at me, hoping this makes cross-compilers happy.

Acked-by: David Hildenbrand <david@redhat.com>

-- 
Cheers

David / dhildenb