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>

1 files changed, 3 insertions, 3 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 6aaf657adb87..36c85e04fa93 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -232,7 +232,7 @@ static struct vm_area_struct *remove_vma(struct vm_area_struct *vma)
                 vma->vm_ops->close(vma);
         if (vma->vm_file)
                 fput(vma->vm_file);
-        mpol_free(vma_policy(vma));
+        mpol_put(vma_policy(vma));
         kmem_cache_free(vm_area_cachep, vma);
         return next;
 }
@@ -626,7 +626,7 @@ again:			remove_next = 1 + (end > next->vm_end);
                 if (file)
                         fput(file);
                 mm->map_count--;
-                mpol_free(vma_policy(next));
+                mpol_put(vma_policy(next));
                 kmem_cache_free(vm_area_cachep, next);
                 /*
                  * In mprotect's case 6 (see comments on vma_merge),
@@ -1182,7 +1182,7 @@ munmap_back:
 
         if (file && vma_merge(mm, prev, addr, vma->vm_end,
                         vma->vm_flags, NULL, file, pgoff, vma_policy(vma))) {
-                mpol_free(vma_policy(vma));
+                mpol_put(vma_policy(vma));
                 kmem_cache_free(vm_area_cachep, vma);
                 fput(file);
         } else {