On Wed, Mar 17, 2021 at 10:18:40AM +0800, Miaohe Lin wrote:
> Hi:
> On 2021/3/17 4:40, Peter Xu wrote:
> > On Tue, Mar 16, 2021 at 08:40:02AM -0400, Miaohe Lin wrote:
> >> +static inline void split_huge_pmd_if_needed(struct vm_area_struct *vma, unsigned long address)
> >> +{
> >> + /*
> >> + * If the new address isn't hpage aligned and it could previously
> >> + * contain an hugepage: check if we need to split an huge pmd.
> >> + */
> >> + if (address & ~HPAGE_PMD_MASK &&
> >> + range_in_vma(vma, address & HPAGE_PMD_MASK,
> >> + (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE))
> >
> > Since you're at it, maybe use ALIGN/ALIGN_DOWN too against HPAGE_PMD_SIZE?
> >
>
> Many thanks for reply. Sounds good. :) Do you mean this?
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index bff92dea5ab3..ae16a82da823 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2301,44 +2301,38 @@ void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
> __split_huge_pmd(vma, pmd, address, freeze, page);
> }
>
> +static inline void split_huge_pmd_if_needed(struct vm_area_struct *vma, unsigned long address)
> +{
> + /*
> + * If the new address isn't hpage aligned and it could previously
> + * contain an hugepage: check if we need to split an huge pmd.
> + */
> + if (!IS_ALIGNED(address, HPAGE_PMD_SIZE) &&
> + range_in_vma(vma, ALIGN_DOWN(address, HPAGE_PMD_SIZE),
> + ALIGN(address, HPAGE_PMD_SIZE)))
> + split_huge_pmd_address(vma, address, false, NULL);
> +}
> +
Yes. Thanks,
--
Peter Xu
