Hi Sam,
Thanks for review!
On 03/06/2013 03:47 AM, Sam Ravnborg wrote:
> 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?
I will be used in a later patch.
>
>> +
>> +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.
We will introduce another help function named free_highmem_page()
to free highmem into the buddy system. In normal cases __free_reserved_page()
won't be called directly, it's just used to handle several special cases.
>
>
>> +
>> +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.
Good suggestion, will add comments for them.
Regards!
Gerry
>
> Sam
>
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