Re: [PATCH v3 06/16] zsmalloc: squeeze inuse into page->mapping

[Sergey Senozhatsky]

Hello,

On (03/30/16 16:12), Minchan Kim wrote:
[..]
> +static int get_zspage_inuse(struct page *first_page)
> +{
> +	struct zs_meta *m;
> +
> +	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
> +
> +	m = (struct zs_meta *)&first_page->mapping;
..
> +static void set_zspage_inuse(struct page *first_page, int val)
> +{
> +	struct zs_meta *m;
> +
> +	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
> +
> +	m = (struct zs_meta *)&first_page->mapping;
..
> +static void mod_zspage_inuse(struct page *first_page, int val)
> +{
> +	struct zs_meta *m;
> +
> +	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
> +
> +	m = (struct zs_meta *)&first_page->mapping;
..
>  static void get_zspage_mapping(struct page *first_page,
>  				unsigned int *class_idx,
>  				enum fullness_group *fullness)
>  {
> -	unsigned long m;
> +	struct zs_meta *m;
> +
>  	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
> +	m = (struct zs_meta *)&first_page->mapping;
..
>  static void set_zspage_mapping(struct page *first_page,
>  				unsigned int class_idx,
>  				enum fullness_group fullness)
>  {
> +	struct zs_meta *m;
> +
>  	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
>  
> +	m = (struct zs_meta *)&first_page->mapping;
> +	m->fullness = fullness;
> +	m->class = class_idx;
>  }


a nitpick: this

	struct zs_meta *m;
	VM_BUG_ON_PAGE(!is_first_page(first_page), first_page);
	m = (struct zs_meta *)&first_page->mapping;


seems to be common in several places, may be it makes sense to
factor it out and turn into a macro or a static inline helper?

other than that, looks good to me

Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>

	-ss