Re: [PATCH v4 08/34] mm: Convert ptlock_ptr() to use ptdescs

[Mike Rapoport <rppt@xxxxxxxxxx>]

On Mon, Jun 12, 2023 at 02:03:57PM -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) <vishal.moola@xxxxxxxxx>

Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

> ---
>  arch/x86/xen/mmu_pv.c |  2 +-
>  include/linux/mm.h    | 14 +++++++-------
>  2 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c
> index b3b8d289b9ab..f469862e3ef4 100644
> --- a/arch/x86/xen/mmu_pv.c
> +++ b/arch/x86/xen/mmu_pv.c
> @@ -651,7 +651,7 @@ static spinlock_t *xen_pte_lock(struct page *page, struct 
> mm_struct *mm)
>       spinlock_t *ptl = NULL;
>  
>  #if USE_SPLIT_PTE_PTLOCKS
> -     ptl = ptlock_ptr(page);
> +     ptl = ptlock_ptr(page_ptdesc(page));
>       spin_lock_nest_lock(ptl, &mm->page_table_lock);
>  #endif
>  
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index e6f1be2a405e..bb934d51390f 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2828,9 +2828,9 @@ void __init ptlock_cache_init(void);
>  bool ptlock_alloc(struct ptdesc *ptdesc);
>  extern void ptlock_free(struct page *page);
>  
> -static inline spinlock_t *ptlock_ptr(struct page *page)
> +static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc)
>  {
> -     return page->ptl;
> +     return ptdesc->ptl;
>  }
>  #else /* ALLOC_SPLIT_PTLOCKS */
>  static inline void ptlock_cache_init(void)
> @@ -2846,15 +2846,15 @@ static inline void ptlock_free(struct page *page)
>  {
>  }
>  
> -static inline spinlock_t *ptlock_ptr(struct page *page)
> +static inline spinlock_t *ptlock_ptr(struct ptdesc *ptdesc)
>  {
> -     return &page->ptl;
> +     return &ptdesc->ptl;
>  }
>  #endif /* ALLOC_SPLIT_PTLOCKS */
>  
>  static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  {
> -     return ptlock_ptr(pmd_page(*pmd));
> +     return ptlock_ptr(page_ptdesc(pmd_page(*pmd)));
>  }
>  
>  static inline bool ptlock_init(struct page *page)
> @@ -2869,7 +2869,7 @@ static inline bool ptlock_init(struct page *page)
>       VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
>       if (!ptlock_alloc(page_ptdesc(page)))
>               return false;
> -     spin_lock_init(ptlock_ptr(page));
> +     spin_lock_init(ptlock_ptr(page_ptdesc(page)));
>       return true;
>  }
>  
> @@ -2939,7 +2939,7 @@ static inline struct ptdesc *pmd_ptdesc(pmd_t *pmd)
>  
>  static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
>  {
> -     return ptlock_ptr(ptdesc_page(pmd_ptdesc(pmd)));
> +     return ptlock_ptr(pmd_ptdesc(pmd));
>  }
>  
>  static inline bool pmd_ptlock_init(struct page *page)
> -- 
> 2.40.1
> 
> 

-- 
Sincerely yours,
Mike.