pagemap: return map count, not reference count, in /proc/kpagecount

Since pagemap is all about examining pages mapped into processes' memory
spaces, it makes sense for kpagecount to return the map counts, not the
reference counts.

Signed-off-by: Thomas Tuttle <ttuttle@google.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index 32dc14c..5a16090 100644 (file)
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -726,7 +726,7 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
                if (!ppage)
                        pcount = 0;
                else
-                       pcount = atomic_read(&ppage->_count);
+                       pcount = page_mapcount(ppage);
 
                if (put_user(pcount, out++)) {
                        ret = -EFAULT;