Re: [RFC 6/8] Account for pages in the page cache in terms of base pages

["Nish Aravamudan" <nish.aravamudan@gmail.com>]

On 4/19/07, Christoph Lameter <clameter@sgi.com> wrote:
> Variable Order Page Cache: Account for higher order pages
>
> NR_FILE_PAGES now counts pages of different order. Maybe we need to
> account in base page sized pages? If so then we need to change
> the way we update the counters. Note that the same would have to be
> done for other counters.
>
> Signed-off-by: Christoph Lameter <clameter@sgi.com>
>
>
> ---
>  mm/filemap.c |    6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> Index: linux-2.6.21-rc7/mm/filemap.c
> ===================================================================
> --- linux-2.6.21-rc7.orig/mm/filemap.c  2007-04-19 09:11:13.000000000 -0700
> +++ linux-2.6.21-rc7/mm/filemap.c       2007-04-19 09:14:16.000000000 -0700
> @@ -119,7 +119,8 @@ void __remove_from_page_cache(struct pag
>         radix_tree_delete(&mapping->page_tree, page->index);
>         page->mapping = NULL;
>         mapping->nrpages--;
> -       __dec_zone_page_state(page, NR_FILE_PAGES);
> +       __mod_zone_page_state(page_zone(page), NR_FILE_PAGES,
> +                       -(1 << mapping->order));
>  }
>
>  void remove_from_page_cache(struct page *page)
> @@ -448,7 +449,8 @@ int add_to_page_cache(struct page *page,
>                         page->mapping = mapping;
>                         page->index = offset;
>                         mapping->nrpages++;
> -                       __inc_zone_page_state(page, NR_FILE_PAGES);
> +                       __mod_zone_page_state(page_zone(page), NR_FILE_PAGES,
> +                                       1 << mappig->order);

Typo? should be mapping->order?

Thanks,
Nish