re #13613 rb4516 Tunables needs volatile keyword

@@ -18,10 +18,11 @@
  *
  * CDDL HEADER END
  */
 /*
  * Copyright (c) 1995, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
  */
 
 /*
  * UNIX machine dependent virtual memory support.
  */

@@ -572,11 +573,11 @@
 extern int ecache_alignsize;
 #define L2CACHE_ALIGN           ecache_alignsize
 #define L2CACHE_ALIGN_MAX       512
 
 extern int update_proc_pgcolorbase_after_fork;
-extern int consistent_coloring;
+extern volatile int consistent_coloring;
 extern uint_t vac_colors_mask;
 extern int vac_size;
 extern int vac_shift;
 
 /*