mm: accurately document nr_free_*_pages functions with code comments

nr_free_zone_pages(), nr_free_buffer_pages() and nr_free_pagecache_pages()
are horribly badly named, so accurately document them with code comments
in case of the misuse of them.

[akpm@linux-foundation.org: tweak comments]
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Zhang Yanfei 2013-02-22 16:35:54 -08:00 committed by Linus Torvalds
parent 5f4b9fc5c1
commit e0fb581529

View File

@ -2813,6 +2813,15 @@ void free_pages_exact(void *virt, size_t size)
}
EXPORT_SYMBOL(free_pages_exact);
/**
* nr_free_zone_pages - count number of pages beyond high watermark
* @offset: The zone index of the highest zone
*
* nr_free_zone_pages() counts the number of counts pages which are beyond the
* high watermark within all zones at or below a given zone index. For each
* zone, the number of pages is calculated as:
* present_pages - high_pages
*/
static unsigned long nr_free_zone_pages(int offset)
{
struct zoneref *z;
@ -2833,8 +2842,11 @@ static unsigned long nr_free_zone_pages(int offset)
return sum;
}
/*
* Amount of free RAM allocatable within ZONE_DMA and ZONE_NORMAL
/**
* nr_free_buffer_pages - count number of pages beyond high watermark
*
* nr_free_buffer_pages() counts the number of pages which are beyond the high
* watermark within ZONE_DMA and ZONE_NORMAL.
*/
unsigned long nr_free_buffer_pages(void)
{
@ -2842,8 +2854,11 @@ unsigned long nr_free_buffer_pages(void)
}
EXPORT_SYMBOL_GPL(nr_free_buffer_pages);
/*
* Amount of free RAM allocatable within all zones
/**
* nr_free_pagecache_pages - count number of pages beyond high watermark
*
* nr_free_pagecache_pages() counts the number of pages which are beyond the
* high watermark within all zones.
*/
unsigned long nr_free_pagecache_pages(void)
{