Re: [PATCH v2] page cache: Store only head pages in i_pages

[Kirill A. Shutemov]

On Thu, Feb 14, 2019 at 01:17:57PM -0800, Matthew Wilcox wrote:
> On Thu, Feb 14, 2019 at 04:30:04PM +0300, Kirill A. Shutemov wrote:
> >  - migrate_page_move_mapping() has to be converted too.
> 
> I think that's as simple as:
> 
> +++ b/mm/migrate.c
> @@ -465,7 +465,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
>  
>                 for (i = 1; i < HPAGE_PMD_NR; i++) {
>                         xas_next(&xas);
> -                       xas_store(&xas, newpage + i);
> +                       xas_store(&xas, newpage);
>                 }
>         }
>  
> 
> or do you see something else I missed?

Looks right to me.

BTW, maybe some add syntax sugar from XArray side?

Replace the loop and xas_store() before it with:

		xas_fill(&xas, newpage, 1UL << compound_order(newpage));

or something similar?

-- 
 Kirill A. Shutemov