re #13613 rb4516 Tunables needs volatile keyword

*** 21,30 ****
--- 21,33 ----
   */
  /*
   * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
+ /*
+  * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
+  */
  
  /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  /*        All Rights Reserved   */
  
  
*** 36,50 ****
  #endif
  
  /*
   * pointer to swapfs global data structures
   */
! extern pgcnt_t swapfs_minfree;          /* amount of availrmem (in pages) */
                                          /* that is unavailable to swapfs */
  extern pgcnt_t swapfs_desfree;
  
! extern pgcnt_t swapfs_reserve;          /* amount of availrmem (in pages) */
                                          /* that is unavailable for swap */
                                          /* reservation to non-priv processes */
  
  extern struct vnodeops *swap_vnodeops;
  extern struct vnode *swapfs_getvp(ulong_t);
--- 39,53 ----
  #endif
  
  /*
   * pointer to swapfs global data structures
   */
! extern volatile pgcnt_t swapfs_minfree; /* amount of availrmem (in pages) */
                                          /* that is unavailable to swapfs */
  extern pgcnt_t swapfs_desfree;
  
! extern volatile pgcnt_t swapfs_reserve; /* amount of availrmem (in pages) */
                                          /* that is unavailable for swap */
                                          /* reservation to non-priv processes */
  
  extern struct vnodeops *swap_vnodeops;
  extern struct vnode *swapfs_getvp(ulong_t);