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

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

[Minchan Kim]

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 at 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(+)

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)
+
 #define PMD_BIT_FUNC(fn,op) \
 static inline pmd_t pmd_##fn(pmd_t pmd) { pmd_val(pmd) op; return pmd; }
 
@@ -228,6 +230,7 @@ PMD_BIT_FUNC(mkold,	&= ~PMD_SECT_AF);
 PMD_BIT_FUNC(mksplitting, |= PMD_SECT_SPLITTING);
 PMD_BIT_FUNC(mkwrite,   &= ~PMD_SECT_RDONLY);
 PMD_BIT_FUNC(mkdirty,   |= PMD_SECT_DIRTY);
+PMD_BIT_FUNC(mkclean,   &= ~PMD_SECT_DIRTY);
 PMD_BIT_FUNC(mkyoung,   |= PMD_SECT_AF);
 
 #define pmd_mkhuge(pmd)		(__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 579702086488..f3ec01cef04f 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -240,10 +240,12 @@ static inline pmd_t pte_pmd(pte_t pte)
 #endif
 
 #define pmd_young(pmd)		pte_young(pmd_pte(pmd))
+#define pmd_dirty(pmd)		pte_dirty(pmd_pte(pmd))
 #define pmd_wrprotect(pmd)	pte_pmd(pte_wrprotect(pmd_pte(pmd)))
 #define pmd_mksplitting(pmd)	pte_pmd(pte_mkspecial(pmd_pte(pmd)))
 #define pmd_mkold(pmd)		pte_pmd(pte_mkold(pmd_pte(pmd)))
 #define pmd_mkwrite(pmd)	pte_pmd(pte_mkwrite(pmd_pte(pmd)))
+#define pmd_mkclean(pmd)	pte_pmd(pte_mkclean(pmd_pte(pmd)))
 #define pmd_mkdirty(pmd)	pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 #define pmd_mkyoung(pmd)	pte_pmd(pte_mkyoung(pmd_pte(pmd)))
 #define pmd_mknotpresent(pmd)	(__pmd(pmd_val(pmd) & ~PMD_TYPE_MASK))
-- 
2.0.0

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

[Steve Capper]

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 at 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 

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

[Minchan Kim]

Hello Steve,

On Tue, Jul 08, 2014 at 12:37:38PM +0100, Steve Capper wrote:
> 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 at 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?
> 

Sure.

> 
> > 
> > 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
> 

Oops, will fix.

Thanks for the review!

> 
> Cheers,
> -- 
> Steve 
> 
> --
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-- 
Kind regards,
Minchan Kim