On Tue, Mar 05, 2013 at 10:54:44PM +0800, Jiang Liu wrote:
> Code to deal with reserved/managed pages are duplicated by many
> architectures, so introduce common help functions to reduce duplicated
> code. These common help functions will also be used to concentrate code
> to modify totalram_pages and zone->managed_pages, which makes the code
> much more clear.
>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
> ---
> include/linux/mm.h | 37 +++++++++++++++++++++++++++++++++++++
> mm/page_alloc.c | 20 ++++++++++++++++++++
> 2 files changed, 57 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 7acc9dc..881461c 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -1295,6 +1295,43 @@ extern void free_area_init_node(int nid, unsigned long * zones_size,
> unsigned long zone_start_pfn, unsigned long *zholes_size);
> extern void free_initmem(void);
>
> +/* Help functions to deal with reserved/managed pages. */
> +extern unsigned long free_reserved_area(unsigned long start, unsigned long end,
> + int poison, char *s);
> +
> +static inline void adjust_managed_page_count(struct page *page, long count)
> +{
> + totalram_pages += count;
> +}
What is the purpose of the unused page argument?
> +
> +static inline void __free_reserved_page(struct page *page)
> +{
> + ClearPageReserved(page);
> + init_page_count(page);
> + __free_page(page);
> +}
This method is useful for architectures which implment HIGHMEM,
like 32 bit x86 and 32 bit sparc.
This calls for a name without underscores.
> +
> +static inline void free_reserved_page(struct page *page)
> +{
> + __free_reserved_page(page);
> + adjust_managed_page_count(page, 1);
> +}
> +
> +static inline void mark_page_reserved(struct page *page)
> +{
> + SetPageReserved(page);
> + adjust_managed_page_count(page, -1);
> +}
> +
> +static inline void free_initmem_default(int poison)
> +{
Why request user to supply the poison argumet. If this is the default
implmentation then use the default poison value too (POISON_FREE_INITMEM)
> + extern char __init_begin[], __init_end[];
> +
> + free_reserved_area(PAGE_ALIGN((unsigned long)&__init_begin) ,
> + ((unsigned long)&__init_end) & PAGE_MASK,
> + poison, "unused kernel");
> +}
Maybe it is just me how is not used to this area of the kernel.
But a few comments that describe what the purpose is of each
function would have helped me.
Sam
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