First phase of removing the PG_COPYONWRITE flag, and an architectural

cleanup of mapping files.

3 files changed, 19 insertions, 55 deletions

diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index 23e0961..efd63fa 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -66,7 +66,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- * $Id: vm_fault.c,v 1.32 1995/09/24 19:47:58 dyson Exp $
+ * $Id: vm_fault.c,v 1.33 1995/10/07 19:02:53 davidg Exp $
  */
 
 /*
@@ -532,7 +532,6 @@ readrest:
 			object->paging_in_progress++;
 		} else {
 			prot &= ~VM_PROT_WRITE;
-			m->flags |= PG_COPYONWRITE;
 		}
 	}
 
@@ -590,19 +589,12 @@ readrest:
 		 * write-enabled after all.
 		 */
 		prot &= retry_prot;
-		if (m->flags & PG_COPYONWRITE)
-			prot &= ~VM_PROT_WRITE;
 	}
 	/*
 	 * (the various bits we're fiddling with here are locked by the
 	 * object's lock)
 	 */
 
-	/* XXX This distorts the meaning of the copy_on_write bit */
-
-	if (prot & VM_PROT_WRITE)
-		m->flags &= ~PG_COPYONWRITE;
-
 	/*
 	 * It's critically important that a wired-down page be faulted only
 	 * once in each map for which it is wired.
diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
index fb955fe..fed73e0 100644
--- a/sys/vm/vm_mmap.c
+++ b/sys/vm/vm_mmap.c
@@ -38,7 +38,7 @@
  * from: Utah $Hdr: vm_mmap.c 1.6 91/10/21$
  *
  *	@(#)vm_mmap.c	8.4 (Berkeley) 1/12/94
- * $Id: vm_mmap.c,v 1.26 1995/07/13 08:48:31 davidg Exp $
+ * $Id: vm_mmap.c,v 1.27 1995/10/21 17:42:28 dyson Exp $
  */
 
 /*
@@ -636,50 +636,31 @@ vm_mmap(map, addr, size, prot, maxprot, flags, handle, foff)
 	if (object == NULL)
 		return (type == OBJT_DEVICE ? EINVAL : ENOMEM);
 
-	/*
-	 * Anonymous memory, shared file, or character special file.
-	 */
-	if ((flags & (MAP_ANON|MAP_SHARED)) || (type == OBJT_DEVICE)) {
-		rv = vm_map_find(map, object, foff, addr, size, fitit);
-		if (rv != KERN_SUCCESS) {
-			/*
-			 * Lose the object reference. Will destroy the
-			 * object if it's an unnamed anonymous mapping
-			 * or named anonymous without other references.
-			 */
-			vm_object_deallocate(object);
-			goto out;
-		}
+	rv = vm_map_find(map, object, foff, addr, size, fitit);
+	if (rv != KERN_SUCCESS) {
+		/*
+		 * Lose the object reference. Will destroy the
+		 * object if it's an unnamed anonymous mapping
+		 * or named anonymous without other references.
+		 */
+		vm_object_deallocate(object);
+		goto out;
 	}
+
 	/*
 	 * mmap a COW regular file
 	 */
-	else {
+	if ((flags & (MAP_ANON|MAP_SHARED)) == 0 && (type != OBJT_DEVICE)) {
 		vm_map_entry_t entry;
-		vm_object_t private_object;
-
-		/*
-		 * Create a new object and make the original object
-		 * the backing object. NOTE: the object reference gained
-		 * above is now changed into the reference held by
-		 * private_object. Since we don't map 'object', we want
-		 * only this one reference.
-		 */
-		private_object = vm_object_allocate(OBJT_DEFAULT, object->size);
-		private_object->backing_object = object;
-		TAILQ_INSERT_TAIL(&object->shadow_head,
-			    private_object, shadow_list);
-
-		rv = vm_map_find(map, private_object, foff, addr, size, fitit);
-		if (rv != KERN_SUCCESS) {
-			vm_object_deallocate(private_object);
-			goto out;
-		}
-
 		if (!vm_map_lookup_entry(map, *addr, &entry)) {
 			panic("vm_mmap: missing map entry!!!");
 		}
 		entry->copy_on_write = TRUE;
+		/*
+		 * This will create the processes private object on
+		 * an as needed basis.
+		 */
+		entry->needs_copy = TRUE;
 
 		/*
 		 * set pages COW and protect for read access only
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index 9a70cf1..b6f3954 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -61,7 +61,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- * $Id: vm_object.c,v 1.52 1995/08/16 16:14:28 bde Exp $
+ * $Id: vm_object.c,v 1.53 1995/08/26 23:19:48 bde Exp $
  */
 
 /*
@@ -615,7 +615,6 @@ vm_object_pmap_copy(object, start, end)
 	for (p = object->memq.tqh_first; p != NULL; p = p->listq.tqe_next) {
 		if ((start <= p->offset) && (p->offset < end)) {
 			vm_page_protect(p, VM_PROT_READ);
-			p->flags |= PG_COPYONWRITE;
 		}
 	}
 }
@@ -709,14 +708,6 @@ vm_object_copy(src_object, src_offset, size,
 	 */
 	src_object->ref_count++;
 
-	/*
-	 * Mark all of the pages copy-on-write.
-	 */
-	for (p = src_object->memq.tqh_first; p; p = p->listq.tqe_next)
-		if (src_offset <= p->offset &&
-		    p->offset < src_offset + size)
-			p->flags |= PG_COPYONWRITE;
-
 	*dst_object = src_object;
 	*dst_offset = src_offset;