--- Net2/vm/vm_page.c	2018/04/24 18:03:57	1.1
+++ Net2/vm/vm_page.c	2018/04/24 18:15:00	1.1.1.4
@@ -33,7 +33,8 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)vm_page.c	7.4 (Berkeley) 5/7/91
+ *	from: @(#)vm_page.c	7.4 (Berkeley) 5/7/91
+ *	vm_page.c,v 1.5 1993/06/30 03:48:25 andrew Exp
  *
  *
  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
@@ -204,7 +205,7 @@ vm_offset_t vm_page_startup(start, end,
 	vaddr = pmap_map(mapped, start, new_start,
 			VM_PROT_READ|VM_PROT_WRITE);
 	start = new_start;
-	blkclr((caddr_t) mapped, vaddr - mapped);
+	bzero((caddr_t) mapped, vaddr - mapped);
 	mapped = vaddr;
 
 	for (i = vm_page_bucket_count; i--;) {
@@ -244,7 +245,7 @@ vm_offset_t vm_page_startup(start, end,
 
 	new_start = start + (vaddr - mapped);
 	pmap_map(mapped, start, new_start, VM_PROT_READ|VM_PROT_WRITE);
-	blkclr((caddr_t) mapped, (vaddr - mapped));
+	bzero((caddr_t) mapped, (vaddr - mapped));
 	mapped = vaddr;
 	start = new_start;
 
@@ -255,7 +256,7 @@ vm_offset_t vm_page_startup(start, end,
 	 */
 
 	vm_page_free_count = npages =
-		(end - start)/(PAGE_SIZE + sizeof(struct vm_page));
+		(end - start + sizeof(struct vm_page))/(PAGE_SIZE + sizeof(struct vm_page));
 
 	/*
 	 *	Initialize the mem entry structures now, and
@@ -283,7 +284,7 @@ vm_offset_t vm_page_startup(start, end,
 	/*
 	 *	Clear all of the page structures
 	 */
-	blkclr((caddr_t)m, npages * sizeof(*m));
+	bzero((caddr_t)m, npages * sizeof(*m));
 
 	pa = first_phys_addr;
 	while (npages--) {
@@ -547,6 +548,14 @@ vm_page_t vm_page_alloc(object, offset)
 
 	spl = splimp();				/* XXX */
 	simple_lock(&vm_page_queue_free_lock);
+	if (	object != kernel_object &&
+		object != kmem_object	&&
+		vm_page_free_count <= vm_page_free_reserved) {
+
+		simple_unlock(&vm_page_queue_free_lock);
+		splx(spl);
+		return(NULL);
+	}
 	if (queue_empty(&vm_page_queue_free)) {
 		simple_unlock(&vm_page_queue_free_lock);
 		splx(spl);
@@ -687,15 +696,22 @@ void vm_page_deactivate(m)
 	/*
 	 *	Only move active pages -- ignore locked or already
 	 *	inactive ones.
+	 *
+	 *	XXX: sometimes we get pages which aren't wired down
+	 *	or on any queue - we need to put them on the inactive
+	 *	queue also, otherwise we lose track of them.
+	 *	Paul Mackerras (paulus@cs.anu.edu.au) 9-Jan-93.
 	 */
 
-	if (m->active) {
+	if (!m->inactive && m->wire_count == 0) {
 		pmap_clear_reference(VM_PAGE_TO_PHYS(m));
-		queue_remove(&vm_page_queue_active, m, vm_page_t, pageq);
+		if (m->active) {
+			queue_remove(&vm_page_queue_active, m, vm_page_t, pageq);
+			m->active = FALSE;
+			vm_page_active_count--;
+		}
 		queue_enter(&vm_page_queue_inactive, m, vm_page_t, pageq);
-		m->active = FALSE;
 		m->inactive = TRUE;
-		vm_page_active_count--;
 		vm_page_inactive_count++;
 		if (pmap_is_modified(VM_PAGE_TO_PHYS(m)))
 			m->clean = FALSE;