Re: [PATCH RFC v3 01/35] mm: page_alloc: Add gfp_flags parameter to arch_alloc_page()

[Anshuman Khandual]

On 1/25/24 22:12, Alexandru Elisei wrote:
> Extend the usefulness of arch_alloc_page() by adding the gfp_flags
> parameter.

Although the change here is harmless in itself, it will definitely benefit
from some additional context explaining the rationale, taking into account
why-how arch_alloc_page() got added particularly for s390 platform and how
it's going to be used in the present proposal.

> 
> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> ---
> 
> Changes since rfc v2:
> 
> * New patch.
> 
>  arch/s390/include/asm/page.h | 2 +-
>  arch/s390/mm/page-states.c   | 2 +-
>  include/linux/gfp.h          | 2 +-
>  mm/page_alloc.c              | 2 +-
>  4 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
> index 73b9c3bf377f..859f0958c574 100644
> --- a/arch/s390/include/asm/page.h
> +++ b/arch/s390/include/asm/page.h
> @@ -163,7 +163,7 @@ static inline int page_reset_referenced(unsigned long addr)
>  
>  struct page;
>  void arch_free_page(struct page *page, int order);
> -void arch_alloc_page(struct page *page, int order);
> +void arch_alloc_page(struct page *page, int order, gfp_t gfp_flags);
>  
>  static inline int devmem_is_allowed(unsigned long pfn)
>  {
> diff --git a/arch/s390/mm/page-states.c b/arch/s390/mm/page-states.c
> index 01f9b39e65f5..b986c8b158e3 100644
> --- a/arch/s390/mm/page-states.c
> +++ b/arch/s390/mm/page-states.c
> @@ -21,7 +21,7 @@ void arch_free_page(struct page *page, int order)
>  	__set_page_unused(page_to_virt(page), 1UL << order);
>  }
>  
> -void arch_alloc_page(struct page *page, int order)
> +void arch_alloc_page(struct page *page, int order, gfp_t gfp_flags)
>  {
>  	if (!cmma_flag)
>  		return;
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index de292a007138..9e8aa3d144db 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -172,7 +172,7 @@ static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
>  static inline void arch_free_page(struct page *page, int order) { }
>  #endif
>  #ifndef HAVE_ARCH_ALLOC_PAGE
> -static inline void arch_alloc_page(struct page *page, int order) { }
> +static inline void arch_alloc_page(struct page *page, int order, gfp_t gfp_flags) { }
>  #endif
>  
>  struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid,
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 150d4f23b010..2c140abe5ee6 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1485,7 +1485,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
>  	set_page_private(page, 0);
>  	set_page_refcounted(page);
>  
> -	arch_alloc_page(page, order);
> +	arch_alloc_page(page, order, gfp_flags);
>  	debug_pagealloc_map_pages(page, 1 << order);
>  
>  	/*

Otherwise LGTM.