Re: [PATCH 14 of 31] add pmd mangling generic functions

[Mel Gorman <mel@csn.ul.ie>]

On Tue, Jan 26, 2010 at 02:52:09PM +0100, Andrea Arcangeli wrote:
> From: Andrea Arcangeli <aarcange@redhat.com>
> 
> Some are needed to build but not actually used on archs not supporting
> transparent hugepages. Others like pmdp_clear_flush are used by x86 too.
> 

If they are not used, why are they needed to build?

> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
> ---
> 
> diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
> --- a/include/asm-generic/pgtable.h
> +++ b/include/asm-generic/pgtable.h
> @@ -23,6 +23,19 @@
>  	}								  \
>  	__changed;							  \
>  })
> +
> +#define pmdp_set_access_flags(__vma, __address, __pmdp, __entry, __dirty) \
> +	({								\
> +		int __changed = !pmd_same(*(__pmdp), __entry);		\
> +		VM_BUG_ON((__address) & ~HPAGE_PMD_MASK);		\
> +		if (__changed) {					\
> +			set_pmd_at((__vma)->vm_mm, __address, __pmdp,	\
> +				   __entry);				\
> +			flush_tlb_range(__vma, __address,		\
> +					(__address) + HPAGE_PMD_SIZE);	\
> +		}							\
> +		__changed;						\
> +	})
>  #endif
>  
>  #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
> @@ -37,6 +50,17 @@
>  			   (__ptep), pte_mkold(__pte));			\
>  	r;								\
>  })
> +#define pmdp_test_and_clear_young(__vma, __address, __pmdp)		\
> +({									\
> +	pmd_t __pmd = *(__pmdp);					\
> +	int r = 1;							\
> +	if (!pmd_young(__pmd))						\
> +		r = 0;							\
> +	else								\
> +		set_pmd_at((__vma)->vm_mm, (__address),			\
> +			   (__pmdp), pmd_mkold(__pmd));			\
> +	r;								\
> +})
>  #endif
>  
>  #ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
> @@ -48,6 +72,16 @@
>  		flush_tlb_page(__vma, __address);			\
>  	__young;							\
>  })
> +#define pmdp_clear_flush_young(__vma, __address, __pmdp)		\
> +({									\
> +	int __young;							\
> +	VM_BUG_ON((__address) & ~HPAGE_PMD_MASK);			\
> +	__young = pmdp_test_and_clear_young(__vma, __address, __pmdp);	\
> +	if (__young)							\
> +		flush_tlb_range(__vma, __address,			\
> +				(__address) + HPAGE_PMD_SIZE);		\
> +	__young;							\
> +})
>  #endif
>  
>  #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
> @@ -57,6 +91,13 @@
>  	pte_clear((__mm), (__address), (__ptep));			\
>  	__pte;								\
>  })
> +
> +#define pmdp_get_and_clear(__mm, __address, __pmdp)			\
> +({									\
> +	pmd_t __pmd = *(__pmdp);					\
> +	pmd_clear((__mm), (__address), (__pmdp));			\
> +	__pmd;								\
> +})
>  #endif
>  
>  #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
> @@ -88,6 +129,15 @@ do {									\
>  	flush_tlb_page(__vma, __address);				\
>  	__pte;								\
>  })
> +
> +#define pmdp_clear_flush(__vma, __address, __pmdp)			\
> +({									\
> +	pmd_t __pmd;							\
> +	VM_BUG_ON((__address) & ~HPAGE_PMD_MASK);			\
> +	__pmd = pmdp_get_and_clear((__vma)->vm_mm, __address, __pmdp);	\
> +	flush_tlb_range(__vma, __address, (__address) + HPAGE_PMD_SIZE);\
> +	__pmd;								\
> +})
>  #endif
>  
>  #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
> @@ -97,10 +147,26 @@ static inline void ptep_set_wrprotect(st
>  	pte_t old_pte = *ptep;
>  	set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
>  }
> +
> +static inline void pmdp_set_wrprotect(struct mm_struct *mm, unsigned long address, pmd_t *pmdp)
> +{
> +	pmd_t old_pmd = *pmdp;
> +	set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
> +}
> +
> +#define pmdp_splitting_flush(__vma, __address, __pmdp)			\
> +({									\
> +	pmd_t __pmd = pmd_mksplitting(*(__pmdp));			\
> +	VM_BUG_ON((__address) & ~HPAGE_PMD_MASK);			\
> +	set_pmd_at((__vma)->vm_mm, __address, __pmdp, __pmd);		\
> +	/* tlb flush only to serialize against gup-fast */		\
> +	flush_tlb_range(__vma, __address, (__address) + HPAGE_PMD_SIZE);\
> +})
>  #endif
>  
>  #ifndef __HAVE_ARCH_PTE_SAME
>  #define pte_same(A,B)	(pte_val(A) == pte_val(B))
> +#define pmd_same(A,B)	(pmd_val(A) == pmd_val(B))
>  #endif
>  
>  #ifndef __HAVE_ARCH_PAGE_TEST_DIRTY
> @@ -344,6 +410,10 @@ extern void untrack_pfn_vma(struct vm_ar
>  				unsigned long size);
>  #endif
>  
> +#ifndef CONFIG_TRANSPARENT_HUGEPAGE
> +#define pmd_write(pmd) 0
> +#endif
> +
>  #endif /* !__ASSEMBLY__ */
>  
>  #endif /* _ASM_GENERIC_PGTABLE_H */
> 

-- 
Mel Gorman
Part-time Phd Student                          Linux Technology Center
University of Limerick                         IBM Dublin Software Lab

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