Re: [PATCH v11 6/7] ARM: add pmd_[dirty|mkclean] for THP

Steve Capper
2014-07-08T11:37:52Z

On Tue, Jul 08, 2014 at 03:03:43PM +0900, Minchan Kim wrote:
> MADV_FREE needs pmd_dirty and pmd_mkclean for detecting recent
> overwrite of the contents since MADV_FREE syscall is called for
> THP page.
>
> This patch adds pmd_dirty and pmd_mkclean for THP page MADV_FREE
> support.
>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Steve Capper <steve.capper@linaro.org>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: linux-arm-kernel@lists.infradead.org
> Signed-off-by: Minchan Kim <minchan@kernel.org>
> ---
> arch/arm/include/asm/pgtable-3level.h | 3 +++
> arch/arm64/include/asm/pgtable.h | 2 ++
> 2 files changed, 5 insertions(+)

Hi Minchan,
arch/arm and arch/arm64 are handled separately.
Could you please split this patch into arm and arm64 versions?

>
> diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
> index 85c60adc8b60..3a7bb8dc7d05 100644
> --- a/arch/arm/include/asm/pgtable-3level.h
> +++ b/arch/arm/include/asm/pgtable-3level.h
> @@ -220,6 +220,8 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
> #define pmd_trans_splitting(pmd) (pmd_val(pmd) & PMD_SECT_SPLITTING)
> #endif
>
> +#define pmd_dirty (pmd_val(pmd) & PMD_SECT_DIRTY)

This macro is missing the parameter definition, and will generate a
compile errror when CONFIG_ARM_LPAE=y

For 32-bit ARM with CONFIG_ARM_LPAE=n, we don't have THP support and I noticed
some compiler errors in mm/madvise.c:

CC mm/madvise.o
mm/madvise.c: In function ‘madvise_free_pte_range’:
mm/madvise.c:279:3: error: implicit declaration of function ‘pmdp_get_and_clear’ [-Werror=implicit-function-declaration]
orig_pmd = pmdp_get_and_clear(mm, addr, pmd);
^
mm/madvise.c:285:3: error: implicit declaration of function ‘pmd_mkold’ [-Werror=implicit-function-declaration]
orig_pmd = pmd_mkold(orig_pmd);
^
mm/madvise.c:286:3: error: implicit declaration of function ‘pmd_mkclean’ [-Werror=implicit-function-declaration]
orig_pmd = pmd_mkclean(orig_pmd);
^
mm/madvise.c:288:3: error: implicit declaration of function ‘set_pmd_at’ [-Werror=implicit-function-declaration]
set_pmd_at(mm, addr, pmd, orig_pmd);
^
cc1: some warnings being treated as errors
make[1]: *** [mm/madvise.o] Error 1

Cheers,
--
Steve