mm: remove MPOL_MF_STATS

Mapping statistics in a NUMA environment is now computed using the generic
walk_page_range() logic.  Remove the old/equivalent functionality.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mempolicy.c

@@ -99,7 +99,6 @@
 /* Internal flags */
 #define MPOL_MF_DISCONTIG_OK (MPOL_MF_INTERNAL << 0)	/* Skip checks for continuous vmas */
 #define MPOL_MF_INVERT (MPOL_MF_INTERNAL << 1)		/* Invert check for nodemask */
-#define MPOL_MF_STATS (MPOL_MF_INTERNAL << 2)		/* Gather statistics */
 
 static struct kmem_cache *policy_cache;
 static struct kmem_cache *sn_cache;
@@ -492,9 +491,7 @@ static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 		if (node_isset(nid, *nodes) == !!(flags & MPOL_MF_INVERT))
 			continue;
 
-		if (flags & MPOL_MF_STATS)
-			gather_stats(page, private, pte_dirty(*pte));
-		else if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
+		if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL))
 			migrate_page_add(page, private, flags);
 		else
 			break;