Re: [PATCH v4 10/34] mm: Convert ptlock_init() to use ptdescs

On Mon, Jun 12, 2023 at 02:03:59PM -0700, Vishal Moola (Oracle) wrote:
> This removes some direct accesses to struct page, working towards
> splitting out struct ptdesc from struct page.
> 
> Signed-off-by: Vishal Moola (Oracle) <[email protected]>

Acked-by: Mike Rapoport (IBM) <[email protected]>

> ---
>  include/linux/mm.h | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index daecf1db6cf1..f48e626d9c98 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2857,7 +2857,7 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  	return ptlock_ptr(page_ptdesc(pmd_page(*pmd)));
>  }
>  
> -static inline bool ptlock_init(struct page *page)
> +static inline bool ptlock_init(struct ptdesc *ptdesc)
>  {
>  	/*
>  	 * prep_new_page() initialize page->private (and therefore page->ptl)
> @@ -2866,10 +2866,10 @@ static inline bool ptlock_init(struct page *page)
>  	 * It can happen if arch try to use slab for page table allocation:
>  	 * slab code uses page->slab_cache, which share storage with page->ptl.
>  	 */
> -	VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
> -	if (!ptlock_alloc(page_ptdesc(page)))
> +	VM_BUG_ON_PAGE(*(unsigned long *)&ptdesc->ptl, ptdesc_page(ptdesc));
> +	if (!ptlock_alloc(ptdesc))
>  		return false;
> -	spin_lock_init(ptlock_ptr(page_ptdesc(page)));
> +	spin_lock_init(ptlock_ptr(ptdesc));
>  	return true;
>  }
>  
> @@ -2882,13 +2882,13 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  	return &mm->page_table_lock;
>  }
>  static inline void ptlock_cache_init(void) {}
> -static inline bool ptlock_init(struct page *page) { return true; }
> +static inline bool ptlock_init(struct ptdesc *ptdesc) { return true; }
>  static inline void ptlock_free(struct page *page) {}
>  #endif /* USE_SPLIT_PTE_PTLOCKS */
>  
>  static inline bool pgtable_pte_page_ctor(struct page *page)
>  {
> -	if (!ptlock_init(page))
> +	if (!ptlock_init(page_ptdesc(page)))
>  		return false;
>  	__SetPageTable(page);
>  	inc_lruvec_page_state(page, NR_PAGETABLE);
> @@ -2947,7 +2947,7 @@ static inline bool pmd_ptlock_init(struct ptdesc *ptdesc)
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>  	ptdesc->pmd_huge_pte = NULL;
>  #endif
> -	return ptlock_init(ptdesc_page(ptdesc));
> +	return ptlock_init(ptdesc);
>  }
>  
>  static inline void pmd_ptlock_free(struct page *page)
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.