Re: [patch 03/19] define page_file_cache() function

Christoph Lameter
2008-01-08T22:19:45Z

On Tue, 8 Jan 2008, Rik van Riel wrote:

> Define page_file_cache() function to answer the question:
> is page backed by a file?

> +static inline int page_file_cache(struct page *page)
> +{
> + if (PageSwapBacked(page))
> + return 0;

Could we call this PageNotFileBacked or so? PageSwapBacked is true for
pages that are RAM based. Its a bit confusing.

> Index: linux-2.6.24-rc6-mm1/mm/migrate.c
> ===================================================================
> --- linux-2.6.24-rc6-mm1.orig/mm/migrate.c 2008-01-02 12:37:14.000000000 -0500
> +++ linux-2.6.24-rc6-mm1/mm/migrate.c 2008-01-02 12:37:22.000000000 -0500
> @@ -546,6 +546,8 @@ static int move_to_new_page(struct page
> /* Prepare mapping for the new page.*/
> newpage->index = page->index;
> newpage->mapping = page->mapping;
> + if (PageSwapBacked(page))
> + SetPageSwapBacked(newpage);
>
> mapping = page_mapping(page);
> if (!mapping)

That hunk belongs into migrate_page_copy()? Or is there a reason that we
need this flag that early?