re #13613 rb4516 Tunables needs volatile keyword

*** 18,27 ****
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1986, 2010, Oracle and/or its affiliates. All rights reserved.
+  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
   */
  
  /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  /*        All Rights Reserved   */
  
*** 672,682 ****
  extern  pgcnt_t total_pages;            /* total pages in the system */
  
  /*
   * Variables controlling locking of physical memory.
   */
! extern  pgcnt_t pages_pp_maximum;       /* tuning: lock + claim <= max */
  extern  void init_pages_pp_maximum(void);
  
  struct lgrp;
  
  /* page_list_{add,sub} flags */
--- 673,683 ----
  extern  pgcnt_t total_pages;            /* total pages in the system */
  
  /*
   * Variables controlling locking of physical memory.
   */
! extern  volatile pgcnt_t pages_pp_maximum; /* tuning: lock + claim <= max */
  extern  void init_pages_pp_maximum(void);
  
  struct lgrp;
  
  /* page_list_{add,sub} flags */