On Thu, Aug 10, 2017 at 06:09:02PM +0100, Punit Agrawal wrote:
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index d3a6713048a2..09e79785c019 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -210,6 +210,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
> pgd_t *pgd;
> pud_t *pud;
> pmd_t *pmd;
> + pte_t *pte;
>
> pgd = pgd_offset(mm, addr);
> pr_debug("%s: addr:0x%lx pgd:%p\n", __func__, addr, pgd);
> @@ -217,19 +218,29 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
> return NULL;
>
> pud = pud_offset(pgd, addr);
> - if (pud_none(*pud))
> + if (pud_none(*pud) && sz != PUD_SIZE)
> return NULL;
> /* swap or huge page */
> if (!pud_present(*pud) || pud_huge(*pud))
> return (pte_t *)pud;
> /* table; check the next level */
So if sz == PUD_SIZE and we have pud_none(*pud) == true, it returns the
pud. Isn't this different from what you proposed for the generic
huge_pte_offset()? [1]
>
> + if (sz == CONT_PMD_SIZE)
> + addr &= CONT_PMD_MASK;
> +
> pmd = pmd_offset(pud, addr);
> - if (pmd_none(*pmd))
> + if (pmd_none(*pmd) &&
> + !(sz == PMD_SIZE || sz == CONT_PMD_SIZE))
> return NULL;
Again, if sz == PMD_SIZE, you no longer return NULL. The generic
proposal in [1] looks like:
if (pmd_none(*pmd))
return NULL;
and that's even when sz == PMD_SIZE.
Anyway, I think we need to push for [1] again to be accepted before we
go ahead with these changes.
[1] http://lkml.kernel.org/r/20170725154114.24131-2-punit.agrawal@xxxxxxx
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Catalin
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