Re: [PATCH 23 of 31] clear_copy_huge_page

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

On Tue, Jan 26, 2010 at 02:52:18PM +0100, Andrea Arcangeli wrote:
> From: Andrea Arcangeli <aarcange@redhat.com>
> 
> Move the copy/clear_huge_page functions to common code to share between
> hugetlb.c and huge_memory.c.
> 
> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>

Acked-by: Mel Gorman <mel@csn.ul.ie>

> ---
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1386,5 +1386,14 @@ extern void shake_page(struct page *p, i
>  extern atomic_long_t mce_bad_pages;
>  extern int soft_offline_page(struct page *page, int flags);
>  
> +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
> +extern void clear_huge_page(struct page *page,
> +			    unsigned long addr,
> +			    unsigned int pages_per_huge_page);
> +extern void copy_huge_page(struct page *dst, struct page *src,
> +			   unsigned long addr, struct vm_area_struct *vma,
> +			   unsigned int pages_per_huge_page);
> +#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
> +
>  #endif /* __KERNEL__ */
>  #endif /* _LINUX_MM_H */
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -385,70 +385,6 @@ static int vma_has_reserves(struct vm_ar
>  	return 0;
>  }
>  
> -static void clear_gigantic_page(struct page *page,
> -			unsigned long addr, unsigned long sz)
> -{
> -	int i;
> -	struct page *p = page;
> -
> -	might_sleep();
> -	for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) {
> -		cond_resched();
> -		clear_user_highpage(p, addr + i * PAGE_SIZE);
> -	}
> -}
> -static void clear_huge_page(struct page *page,
> -			unsigned long addr, unsigned long sz)
> -{
> -	int i;
> -
> -	if (unlikely(sz/PAGE_SIZE > MAX_ORDER_NR_PAGES)) {
> -		clear_gigantic_page(page, addr, sz);
> -		return;
> -	}
> -
> -	might_sleep();
> -	for (i = 0; i < sz/PAGE_SIZE; i++) {
> -		cond_resched();
> -		clear_user_highpage(page + i, addr + i * PAGE_SIZE);
> -	}
> -}
> -
> -static void copy_gigantic_page(struct page *dst, struct page *src,
> -			   unsigned long addr, struct vm_area_struct *vma)
> -{
> -	int i;
> -	struct hstate *h = hstate_vma(vma);
> -	struct page *dst_base = dst;
> -	struct page *src_base = src;
> -	might_sleep();
> -	for (i = 0; i < pages_per_huge_page(h); ) {
> -		cond_resched();
> -		copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
> -
> -		i++;
> -		dst = mem_map_next(dst, dst_base, i);
> -		src = mem_map_next(src, src_base, i);
> -	}
> -}
> -static void copy_huge_page(struct page *dst, struct page *src,
> -			   unsigned long addr, struct vm_area_struct *vma)
> -{
> -	int i;
> -	struct hstate *h = hstate_vma(vma);
> -
> -	if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
> -		copy_gigantic_page(dst, src, addr, vma);
> -		return;
> -	}
> -
> -	might_sleep();
> -	for (i = 0; i < pages_per_huge_page(h); i++) {
> -		cond_resched();
> -		copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
> -	}
> -}
> -
>  static void enqueue_huge_page(struct hstate *h, struct page *page)
>  {
>  	int nid = page_to_nid(page);
> @@ -2334,7 +2270,8 @@ retry_avoidcopy:
>  		return -PTR_ERR(new_page);
>  	}
>  
> -	copy_huge_page(new_page, old_page, address, vma);
> +	copy_huge_page(new_page, old_page, address, vma,
> +		       pages_per_huge_page(h));
>  	__SetPageUptodate(new_page);
>  
>  	/*
> diff --git a/mm/memory.c b/mm/memory.c
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3396,3 +3396,73 @@ void might_fault(void)
>  }
>  EXPORT_SYMBOL(might_fault);
>  #endif
> +
> +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
> +static void clear_gigantic_page(struct page *page,
> +				unsigned long addr,
> +				unsigned int pages_per_huge_page)
> +{
> +	int i;
> +	struct page *p = page;
> +
> +	might_sleep();
> +	for (i = 0; i < pages_per_huge_page;
> +	     i++, p = mem_map_next(p, page, i)) {
> +		cond_resched();
> +		clear_user_highpage(p, addr + i * PAGE_SIZE);
> +	}
> +}
> +void clear_huge_page(struct page *page,
> +		     unsigned long addr, unsigned int pages_per_huge_page)
> +{
> +	int i;
> +
> +	if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
> +		clear_gigantic_page(page, addr, pages_per_huge_page);
> +		return;
> +	}
> +
> +	might_sleep();
> +	for (i = 0; i < pages_per_huge_page; i++) {
> +		cond_resched();
> +		clear_user_highpage(page + i, addr + i * PAGE_SIZE);
> +	}
> +}
> +
> +static void copy_gigantic_page(struct page *dst, struct page *src,
> +			       unsigned long addr,
> +			       struct vm_area_struct *vma,
> +			       unsigned int pages_per_huge_page)
> +{
> +	int i;
> +	struct page *dst_base = dst;
> +	struct page *src_base = src;
> +	might_sleep();
> +	for (i = 0; i < pages_per_huge_page; ) {
> +		cond_resched();
> +		copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
> +
> +		i++;
> +		dst = mem_map_next(dst, dst_base, i);
> +		src = mem_map_next(src, src_base, i);
> +	}
> +}
> +void copy_huge_page(struct page *dst, struct page *src,
> +		    unsigned long addr, struct vm_area_struct *vma,
> +		    unsigned int pages_per_huge_page)
> +{
> +	int i;
> +
> +	if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) {
> +		copy_gigantic_page(dst, src, addr, vma, pages_per_huge_page);
> +		return;
> +	}
> +
> +	might_sleep();
> +	for (i = 0; i < pages_per_huge_page; i++) {
> +		cond_resched();
> +		copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE,
> +				   vma);
> +	}
> +}
> +#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
> 

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

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