# Re: \[PATCH v11 6/7\] ARM: add pmd\_\[dirty\|mkclean\] for THP

- From: Steve Capper \<hidden\>
- Date: 2014-07-08 11:37:52 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2014/07/4289440
- Thread: https://ratatoskr.run/linux-mm/2014/07/4289202/t.md

```text
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 <redacted>
> Cc: Will Deacon <redacted>
> Cc: Steve Capper <redacted>
> Cc: Russell King <redacted>
> Cc: <redacted>
> Signed-off-by: Minchan Kim <redacted>
> ---
>  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 
```