diff options
| author |   Zhang Yanfei <zhangyanfei@cn.fujitsu.com> | 2013-02-22 16:35:54 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-23 17:50:22 -0800 |
| commit | e0fb58152955142f48ed31c8c0541b53e094da6b (patch) | |
| tree | e13fe548e78c694e4d3aa80198f864511233a71e | |
| parent | HWPOISON: change order of error_states[]'s elements (diff) | |
| download | linux-dev-e0fb58152955142f48ed31c8c0541b53e094da6b.tar.xz linux-dev-e0fb58152955142f48ed31c8c0541b53e094da6b.zip | |
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>
| -rw-r--r-- | mm/page_alloc.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 276140654305..e9075fdef695 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -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) { |