Re: [PATCH v2 06/31] arm64: MMU fault handling and page table management

From: Arnd Bergmann
Date: Wed Aug 15 2012 - 09:47:03 EST


On Tuesday 14 August 2012, Catalin Marinas wrote:
> +
> +pgd_t *pgd_alloc(struct mm_struct *mm)
> +{
> + pgd_t *new_pgd;
> +
> + new_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, PGD_ORDER);
> + if (!new_pgd)
> + return NULL;
> +
> + memset(new_pgd, 0, PAGE_SIZE << PGD_ORDER);
> +
> + return new_pgd;
> +}
> +
> +void pgd_free(struct mm_struct *mm, pgd_t *pgd)
> +{
> + free_pages((unsigned long)pgd, PGD_ORDER);
> +}

According to the documentation, you should only need 8kb for the pgd on
a 64kb page system. Is it required that you use up a full page here?

Arnd
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