--- Net2/vm/vm_pageout.h	2018/04/24 18:03:57	1.1.1.1
+++ Net2/vm/vm_pageout.h	2018/04/24 18:15:14	1.1.1.2
@@ -33,7 +33,8 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)vm_pageout.h	7.3 (Berkeley) 4/21/91
+ *	from: @(#)vm_pageout.h	7.3 (Berkeley) 4/21/91
+ *	vm_pageout.h,v 1.3 1993/05/20 03:59:41 cgd Exp
  *
  *
  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
@@ -62,6 +63,9 @@
  * rights to redistribute these changes.
  */
 
+#ifndef _VM_VM_PAGEOUT_H_
+#define _VM_VM_PAGEOUT_H_
+
 /*
  *	Header file for pageout daemon.
  */
@@ -88,3 +92,5 @@ simple_lock_data_t	vm_pages_needed_lock;
 			thread_sleep((int)&vm_page_free_count, \
 				&vm_pages_needed_lock, FALSE); \
 			}
+
+#endif /* !_VM_VM_PAGEOUT_H_ */