Re: [PATCH] mm/thp: Rename TRANSPARENT_HUGEPAGE_NEVER_DAX to _UNSUPPORTED

David Hildenbrand
2023-03-16T14:57:21Z

On 15.03.23 18:16, Peter Xu wrote:
> TRANSPARENT_HUGEPAGE_NEVER_DAX has nothing to do with DAX. It's set when
> has_transparent_hugepage() returns false, checked in hugepage_vma_check()
> and will disable THP completely if false. Rename it to reflect its real
> purpose.
>
> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Cc: Yang Shi <shy828301@gmail.com>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> include/linux/huge_mm.h | 2 +-
> mm/huge_memory.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index 70bd867eba94..9a3a3af2dd80 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -79,7 +79,7 @@ static inline vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn,
> }
>
> enum transparent_hugepage_flag {
> - TRANSPARENT_HUGEPAGE_NEVER_DAX,
> + TRANSPARENT_HUGEPAGE_UNSUPPORTED,
> TRANSPARENT_HUGEPAGE_FLAG,
> TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
> TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index b0ab247939e0..913e7dc32869 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -88,7 +88,7 @@ bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags,
> /*
> * If the hardware/firmware marked hugepage support disabled.
> */
> - if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX))
> + if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED))
> return false;
>
> /* khugepaged doesn't collapse DAX vma, but page fault is fine. */
> @@ -464,7 +464,7 @@ static int __init hugepage_init(void)
> * Hardware doesn't support hugepages, hence disable
> * DAX PMD support.

We should also fixup that comment then, no?

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

--
Thanks,

David / dhildenb