[PATCH] count bounce buffer pages in vmstat

This is a patch for counting the number of pages for bounce buffers.  It's
shown in /proc/vmstat.

Currently, the number of bounce pages are not counted anywhere.  So, if
there are many bounce pages, it seems that there are leaked pages.  And
it's difficult for a user to imagine the usage of bounce pages.  So, it's
meaningful to show # of bouce pages.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 04a35b3..80ce7f2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1897,6 +1897,7 @@
 	"allocstall",
 
 	"pgrotated",
+	"nr_bounce",
 };
 
 static void *vmstat_start(struct seq_file *m, loff_t *pos)