Commit ceddc3a5 authored Sep 21, 2009 by Johannes Weiner Committed by Linus Torvalds Sep 22, 2009

mm: document is_page_cache_freeable()



Enlighten the reader of this code about what reference count makes a page
cache page freeable.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent edcf4748

mm/vmscan.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -286,6 +286,11 @@ static inline int page_mapping_inuse(struct page *page)

		static inline int is_page_cache_freeable(struct page *page)
		{
		/*
		* A freeable page cache page is referenced only by the caller
		* that isolated the page, the page cache radix tree and
		* optional buffer heads at page->private.
		*/
		return page_count(page) - page_has_private(page) == 2;
		}