Re: [PATCH v3 15/44] metag: Huge TLB

From: Dave Hansen
Date: Thu Jan 10 2013 - 11:57:35 EST


On 01/10/2013 07:30 AM, James Hogan wrote:
> +pte_t *huge_pte_alloc(struct mm_struct *mm,
> + unsigned long addr, unsigned long sz)
> +{
> + pgd_t *pgd;
> + pud_t *pud;
> + pmd_t *pmd;
> + pte_t *pte;
> +
> + pgd = pgd_offset(mm, addr);
> + pud = pud_offset(pgd, addr);
> + pmd = pmd_offset(pud, addr);
> + pte = pte_alloc_map(mm, NULL, pmd, addr);
> + pgd->pgd &= ~_PAGE_SZ_MASK;
> + pgd->pgd |= _PAGE_SZHUGE;
> +
> + return pte;
> +}

I'd be a bit surprised if you don't have to check for NULL during the
walk down the page tables. Is there a special reason on your
architecture that this is unnecessary?

(There are several of these, not just this one).

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