Re: [PATCH v16 05/22] mm/thp: move lru_add_page_tail func to huge_memory.c

[Alex Shi <alex.shi@linux.alibaba.com>]

Hi Kirill & Matthew,

Is there any concern from for the THP involved patches?

Thanks
Alex


在 2020/7/11 上午8:58, Alex Shi 写道:
> The func is only used in huge_memory.c, defining it in other file with a
> CONFIG_TRANSPARENT_HUGEPAGE macro restrict just looks weird.
> 
> Let's move it THP. And make it static as Hugh Dickin suggested.
> 
> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: Hugh Dickins <hughd@google.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-mm@kvack.org
> ---
>  include/linux/swap.h |  2 --
>  mm/huge_memory.c     | 30 ++++++++++++++++++++++++++++++
>  mm/swap.c            | 33 ---------------------------------
>  3 files changed, 30 insertions(+), 35 deletions(-)
> 
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 5b3216ba39a9..2c29399b29a0 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -339,8 +339,6 @@ extern void lru_note_cost(struct lruvec *lruvec, bool file,
>  			  unsigned int nr_pages);
>  extern void lru_note_cost_page(struct page *);
>  extern void lru_cache_add(struct page *);
> -extern void lru_add_page_tail(struct page *page, struct page *page_tail,
> -			 struct lruvec *lruvec, struct list_head *head);
>  extern void activate_page(struct page *);
>  extern void mark_page_accessed(struct page *);
>  extern void lru_add_drain(void);
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 78c84bee7e29..9e050b13f597 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2340,6 +2340,36 @@ static void remap_page(struct page *page)
>  	}
>  }
>  
> +static void lru_add_page_tail(struct page *page, struct page *page_tail,
> +				struct lruvec *lruvec, struct list_head *list)
> +{
> +	VM_BUG_ON_PAGE(!PageHead(page), page);
> +	VM_BUG_ON_PAGE(PageCompound(page_tail), page);
> +	VM_BUG_ON_PAGE(PageLRU(page_tail), page);
> +	lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
> +
> +	if (!list)
> +		SetPageLRU(page_tail);
> +
> +	if (likely(PageLRU(page)))
> +		list_add_tail(&page_tail->lru, &page->lru);
> +	else if (list) {
> +		/* page reclaim is reclaiming a huge page */
> +		get_page(page_tail);
> +		list_add_tail(&page_tail->lru, list);
> +	} else {
> +		/*
> +		 * Head page has not yet been counted, as an hpage,
> +		 * so we must account for each subpage individually.
> +		 *
> +		 * Put page_tail on the list at the correct position
> +		 * so they all end up in order.
> +		 */
> +		add_page_to_lru_list_tail(page_tail, lruvec,
> +					  page_lru(page_tail));
> +	}
> +}
> +
>  static void __split_huge_page_tail(struct page *head, int tail,
>  		struct lruvec *lruvec, struct list_head *list)
>  {
> diff --git a/mm/swap.c b/mm/swap.c
> index a82efc33411f..7701d855873d 100644
> --- a/mm/swap.c
> +++ b/mm/swap.c
> @@ -933,39 +933,6 @@ void __pagevec_release(struct pagevec *pvec)
>  }
>  EXPORT_SYMBOL(__pagevec_release);
>  
> -#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -/* used by __split_huge_page_refcount() */
> -void lru_add_page_tail(struct page *page, struct page *page_tail,
> -		       struct lruvec *lruvec, struct list_head *list)
> -{
> -	VM_BUG_ON_PAGE(!PageHead(page), page);
> -	VM_BUG_ON_PAGE(PageCompound(page_tail), page);
> -	VM_BUG_ON_PAGE(PageLRU(page_tail), page);
> -	lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
> -
> -	if (!list)
> -		SetPageLRU(page_tail);
> -
> -	if (likely(PageLRU(page)))
> -		list_add_tail(&page_tail->lru, &page->lru);
> -	else if (list) {
> -		/* page reclaim is reclaiming a huge page */
> -		get_page(page_tail);
> -		list_add_tail(&page_tail->lru, list);
> -	} else {
> -		/*
> -		 * Head page has not yet been counted, as an hpage,
> -		 * so we must account for each subpage individually.
> -		 *
> -		 * Put page_tail on the list at the correct position
> -		 * so they all end up in order.
> -		 */
> -		add_page_to_lru_list_tail(page_tail, lruvec,
> -					  page_lru(page_tail));
> -	}
> -}
> -#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
> -
>  static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec,
>  				 void *arg)
>  {
>