Re: [PATCH] mm: move swp_entry_t definition to include/linux/mm_types.h

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 17 Nov 2014 16:17:23 -0500 Tejun Heo <tj@kernel.org> wrote:

> swp_entry_t being defined in include/linux/swap.h instead of
> include/linux/mm_types.h causes cyclic include dependency later when
> include/linux/page_cgroup.h is included from writeback path.  Move the
> definition to include/linux/mm_types.h.
> 
> While at it, reformat the comment above it.
>
> ...
>
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -525,4 +525,12 @@ enum tlb_flush_reason {
>  	NR_TLB_FLUSH_REASONS,
>  };
>  
> + /*
> +  * A swap entry has to fit into a "unsigned long", as the entry is hidden
> +  * in the "index" field of the swapper address space.
> +  */
> +typedef struct {
> +	unsigned long val;
> +} swp_entry_t;
> +
>  #endif /* _LINUX_MM_TYPES_H */
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -102,14 +102,6 @@ union swap_header {
>  	} info;
>  };
>  
> - /* A swap entry has to fit into a "unsigned long", as
> -  * the entry is hidden in the "index" field of the
> -  * swapper address space.
> -  */
> -typedef struct {
> -	unsigned long val;
> -} swp_entry_t;
> -
>  /*
>   * current->reclaim_state points to one of these when a task is running
>   * memory reclaim

Looks OK to me.  Do you have some patch which depends on this?  If
so, please merge this via whatever tree carries that patch?