On Mon, Oct 15, 2018 at 06:42:37PM +0200, Martin Schwidefsky wrote:
> Add three architecture overrideable function to test if the
> p4d, pud, or pmd layer of a page table is folded or not.
>
> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
> ---
> include/linux/mm.h | 40 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 40 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 0416a7204be3..d1029972541c 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
Shouldn't it be somewhere in asm-generic/pgtable*?
> @@ -105,6 +105,46 @@ extern int mmap_rnd_compat_bits __read_mostly;
> #define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page)))
> #endif
>
> +/*
> + * On some architectures it depends on the mm if the p4d/pud or pmd
> + * layer of the page table hierarchy is folded or not.
> + */
> +#ifndef mm_p4d_folded
> +#define mm_p4d_folded(mm) mm_p4d_folded(mm)
Do we need to define it in generic header?
> +static inline bool mm_p4d_folded(struct mm_struct *mm)
> +{
> +#ifdef __PAGETABLE_P4D_FOLDED
> + return 1;
> +#else
> + return 0;
> +#endif
Maybe
return __is_defined(__PAGETABLE_P4D_FOLDED);
?
--
Kirill A. Shutemov
