Re: [PATCH 5/8] mm: Convert hugetlb_page_mapping_lock_write to folio

[Miaohe Lin <linmiaohe@huawei.com>]

On 2024/3/1 5:20, Matthew Wilcox (Oracle) wrote:
> The page is only used to get the mapping, so the folio will do just
> as well.  Both callers already have a folio available, so this saves
> a call to compound_head().
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Looks good to me. Thanks.

Acked-by: Miaohe Lin <linmiaohe@huawei.com>

> ---
>  include/linux/hugetlb.h | 6 +++---
>  mm/hugetlb.c            | 6 +++---
>  mm/memory-failure.c     | 2 +-
>  mm/migrate.c            | 2 +-
>  4 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 77b30a8c6076..acb1096ecdaa 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -175,7 +175,7 @@ u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx);
>  pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma,
>  		      unsigned long addr, pud_t *pud);
>  
> -struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage);
> +struct address_space *hugetlb_folio_mapping_lock_write(struct folio *folio);
>  
>  extern int sysctl_hugetlb_shm_group;
>  extern struct list_head huge_boot_pages[MAX_NUMNODES];
> @@ -298,8 +298,8 @@ static inline unsigned long hugetlb_total_pages(void)
>  	return 0;
>  }
>  
> -static inline struct address_space *hugetlb_page_mapping_lock_write(
> -							struct page *hpage)
> +static inline struct address_space *hugetlb_folio_mapping_lock_write(
> +							struct folio *folio)
>  {
>  	return NULL;
>  }
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index bb17e5c22759..0e464a8f1aa9 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -2178,13 +2178,13 @@ EXPORT_SYMBOL_GPL(PageHuge);
>  /*
>   * Find and lock address space (mapping) in write mode.
>   *
> - * Upon entry, the page is locked which means that page_mapping() is
> + * Upon entry, the folio is locked which means that folio_mapping() is
>   * stable.  Due to locking order, we can only trylock_write.  If we can
>   * not get the lock, simply return NULL to caller.
>   */
> -struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage)
> +struct address_space *hugetlb_folio_mapping_lock_write(struct folio *folio)
>  {
> -	struct address_space *mapping = page_mapping(hpage);
> +	struct address_space *mapping = folio_mapping(folio);
>  
>  	if (!mapping)
>  		return mapping;
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 27dc21063552..fe4959e994d0 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -1624,7 +1624,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
>  		 * TTU_RMAP_LOCKED to indicate we have taken the lock
>  		 * at this higher level.
>  		 */
> -		mapping = hugetlb_page_mapping_lock_write(hpage);
> +		mapping = hugetlb_folio_mapping_lock_write(folio);
>  		if (mapping) {
>  			try_to_unmap(folio, ttu|TTU_RMAP_LOCKED);
>  			i_mmap_unlock_write(mapping);
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 73a052a382f1..0aef867d600b 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -1425,7 +1425,7 @@ static int unmap_and_move_huge_page(new_folio_t get_new_folio,
>  			 * semaphore in write mode here and set TTU_RMAP_LOCKED
>  			 * to let lower levels know we have taken the lock.
>  			 */
> -			mapping = hugetlb_page_mapping_lock_write(&src->page);
> +			mapping = hugetlb_folio_mapping_lock_write(src);
>  			if (unlikely(!mapping))
>  				goto unlock_put_anon;
>  
>