Re: [PATCH v9 2/3] hugetlb: remove duplicate mmu notifications

[David Hildenbrand]

On 12.11.22 00:26, Mike Kravetz wrote:
> The common hugetlb unmap routine __unmap_hugepage_range performs mmu
> notification calls.  However, in the case where __unmap_hugepage_range
> is called via __unmap_hugepage_range_final, mmu notification calls are
> performed earlier in other calling routines.
>
> Remove mmu notification calls from __unmap_hugepage_range.  Add
> notification calls to the only other caller: unmap_hugepage_range.
> unmap_hugepage_range is called for truncation and hole punch, so
> change notification type from UNMAP to CLEAR as this is more appropriate.
>
> Fixes: 90e7e7f5ef3f ("mm: enable MADV_DONTNEED for hugetlb mappings")
> Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> Reported-by: Wei Chen <harperchen1110@xxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx>

Why exactly do we care about stable backports here? What's the 
user-visible impact?

--
Thanks,

David / dhildenb