lkml.org 
[lkml]   [2007]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Pagecache: find_or_create_page does not call a proper page allocator function
On Mon, 23 Apr 2007 14:11:57 -0700 (PDT)
Christoph Lameter <clameter@sgi.com> wrote:

> The find_or_create function calls alloc_page with a local gfp mask instead
> of using page_cache_alloc. This means that the page allocation will not
> obey cpuset memory spreading and page allocation will not properly use the
> gfp flags in the address space. Highmem is not set correctly.
>
> It turns out that there is no function to allocate a page for the page cache
> with a gfp mask. So we create one ORing the context gfp flags with the gfp flags
> from the mapping.
>
> Signed-off-by: Christoph Lameter <clameter@sgi.com>
>
> ---
> include/linux/pagemap.h | 10 ++++++++--
> mm/filemap.c | 3 ++-
> 2 files changed, 10 insertions(+), 3 deletions(-)
>
> Index: linux-2.6.21-rc7/include/linux/pagemap.h
> ===================================================================
> --- linux-2.6.21-rc7.orig/include/linux/pagemap.h 2007-04-23 13:52:20.000000000 -0700
> +++ linux-2.6.21-rc7/include/linux/pagemap.h 2007-04-23 14:01:09.000000000 -0700
> @@ -60,14 +60,20 @@ static inline struct page *__page_cache_
> }
> #endif
>
> +static inline struct page *page_cache_alloc_mask(struct address_space *x,
> + gfp_t gfp)
> +{
> + return __page_cache_alloc(mapping_gfp_mask(x) | gfp);
> +}

Usually we use the term "mask" to imply an AND function, not an OR
function.

There are few calls to page_cache_alloc(). Would it not be simpler to just
add the additional argument to page_cache_alloc() (called "extra_gfp",
please) and to update all callers? And to remove page_cache_alloc_cold()
and replace all it callers with page_cache_alloc(mapping, __GFP_COLD)?

The way we actually get rid of an API call instead of adding another one.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-04-23 23:31    [W:0.117 / U:0.916 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site