mempolicy: rename mpol_free to mpol_put

This is a change that was requested some time ago by Mel Gorman.  Makes sense
to me, so here it is.

Note: I retain the name "mpol_free_shared_policy()" because it actually does
free the shared_policy, which is NOT a reference counted object.  However, ...

The mempolicy object[s] referenced by the shared_policy are reference counted,
so mpol_put() is used to release the reference held by the shared_policy.  The
mempolicy might not be freed at this time, because some task attached to the
shared object associated with the shared policy may be in the process of
allocating a page based on the mempolicy.  In that case, the task performing
the allocation will hold a reference on the mempolicy, obtained via
mpol_shared_policy_lookup().  The mempolicy will be freed when all tasks
holding such a reference have called mpol_put() for the mempolicy.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 319fd34..507bf5e 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -71,7 +71,7 @@
  *
  * Freeing policy:
  * Mempolicy objects are reference counted.  A mempolicy will be freed when
- * mpol_free() decrements the reference count to zero.
+ * mpol_put() decrements the reference count to zero.
  *
  * Copying policy objects:
  * mpol_copy() allocates a new mempolicy and copies the specified mempolicy
@@ -98,11 +98,11 @@
  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
  */
 
-extern void __mpol_free(struct mempolicy *pol);
-static inline void mpol_free(struct mempolicy *pol)
+extern void __mpol_put(struct mempolicy *pol);
+static inline void mpol_put(struct mempolicy *pol)
 {
 	if (pol)
-		__mpol_free(pol);
+		__mpol_put(pol);
 }
 
 extern struct mempolicy *__mpol_copy(struct mempolicy *pol);
@@ -190,7 +190,7 @@
 	return 1;
 }
 
-static inline void mpol_free(struct mempolicy *p)
+static inline void mpol_put(struct mempolicy *p)
 {
 }