This commit is meant to solve a couple of VM system problems or

performance issues.

	1) The pmap module has had too many inlines, and so the
	   object file is simply bigger than it needs to be.
	   Some common code is also merged into subroutines.
	2) Removal of some *evil* PHYS_TO_VM_PAGE macro calls.
	   Unfortunately, a few have needed to be added also.
	   The removal caused the need for more vm_page_lookups.
	   I added lookup hints to minimize the need for the
	   page table lookup operations.
	3) Removal of some bogus performance improvements, that
	   mostly made the code more complex (tracking individual
	   page table page updates unnecessarily).  Those improvements
	   actually hurt 386 processors perf (not that people who
	   worry about perf use 386 processors anymore :-)).
	4) Changed pv queue manipulations/structures to be TAILQ's.
	5) The pv queue code has had some performance problems since
	   day one.  Some significant scalability issues are resolved
	   by threading the pv entries from the pmap AND the physical
	   address instead of just the physical address.  This makes
	   certain pmap operations run much faster.  This does
	   not affect most micro-benchmarks, but should help loaded system
	   performance *significantly*.  DG helped and came up with most
	   of the solution for this one.
	6) Most if not all pmap bit operations follow the pattern:
		pmap_test_bit();
		pmap_clear_bit();
	   That made for twice the necessary pv list traversal.   The
	   pmap interface now supports only pmap_tc_bit type operations:
	   pmap_[test/clear]_modified, pmap_[test/clear]_referenced.
	   Additionally, the modified routine now takes a vm_page_t arg
	   instead of a phys address.  This eliminates a PHYS_TO_VM_PAGE
	   operation.
	7) Several rewrites of routines that contain redundant code to
	   use common routines, so that there is a greater likelihood of
	   keeping the cache footprint smaller.

1 files changed, 77 insertions, 68 deletions

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 48de311..31455b4 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -61,7 +61,7 @@
  * any improvements or extensions that they make and grant Carnegie the
  * rights to redistribute these changes.
  *
- * $Id: vm_map.c,v 1.51 1996/06/16 20:37:29 dyson Exp $
+ * $Id: vm_map.c,v 1.52 1996/07/07 03:27:41 davidg Exp $
  */
 
 /*
@@ -172,6 +172,8 @@ static void vm_map_entry_unwire __P((vm_map_t, vm_map_entry_t));
 static void vm_map_copy_entry __P((vm_map_t, vm_map_t, vm_map_entry_t,
 		vm_map_entry_t));
 static void vm_map_simplify_entry __P((vm_map_t, vm_map_entry_t));
+static __pure int vm_map_simplify_okay __P((vm_map_entry_t entry1,
+		vm_map_entry_t entry2));
 
 void
 vm_map_startup()
@@ -230,7 +232,6 @@ vmspace_alloc(min, max, pageable)
 	vm_map_init(&vm->vm_map, min, max, pageable);
 	pmap_pinit(&vm->vm_pmap);
 	vm->vm_map.pmap = &vm->vm_pmap;		/* XXX */
-	vm->vm_pmap.pm_map = &vm->vm_map;
 	vm->vm_refcnt = 1;
 	return (vm);
 }
@@ -634,8 +635,8 @@ vm_map_insert(map, object, offset, start, end, prot, max, cow)
 		return (KERN_NO_SPACE);
 
 	if ((prev_entry != &map->header) &&
+		(object == NULL) &&
 		(prev_entry->end == start) &&
-		((object == NULL) || (prev_entry->object.vm_object == object)) &&
 		(prev_entry->is_a_map == FALSE) &&
 		(prev_entry->is_sub_map == FALSE) &&
 		(prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
@@ -648,24 +649,22 @@ vm_map_insert(map, object, offset, start, end, prot, max, cow)
 	 * See if we can avoid creating a new entry by extending one of our
 	 * neighbors.
 	 */
-		if (object == NULL) {
-			if (vm_object_coalesce(prev_entry->object.vm_object,
-				OFF_TO_IDX(prev_entry->offset),
-				(vm_size_t) (prev_entry->end
-				    - prev_entry->start),
-				(vm_size_t) (end - prev_entry->end))) {
+		if (vm_object_coalesce(prev_entry->object.vm_object,
+			OFF_TO_IDX(prev_entry->offset),
+			(vm_size_t) (prev_entry->end
+			    - prev_entry->start),
+			(vm_size_t) (end - prev_entry->end))) {
 
-				/*
-				 * Coalesced the two objects - can extend the
-				 * previous map entry to include the new
-				 * range.
-				 */
-				map->size += (end - prev_entry->end);
-				prev_entry->end = end;
-				prev_object = prev_entry->object.vm_object;
-				default_pager_convert_to_swapq(prev_object);
-				return (KERN_SUCCESS);
-			}
+			/*
+			 * Coalesced the two objects - can extend the
+			 * previous map entry to include the new
+			 * range.
+			 */
+			map->size += (end - prev_entry->end);
+			prev_entry->end = end;
+			prev_object = prev_entry->object.vm_object;
+			default_pager_convert_to_swapq(prev_object);
+			return (KERN_SUCCESS);
 		}
 	}
 	/*
@@ -707,9 +706,10 @@ vm_map_insert(map, object, offset, start, end, prot, max, cow)
 	/*
 	 * Update the free space hint
 	 */
-	if ((map->first_free == prev_entry) &&
-		(prev_entry->end >= new_entry->start))
-		map->first_free = new_entry;
+	if (map->first_free == prev_entry) {
+		if (prev_entry->end == new_entry->start)
+			map->first_free = new_entry;
+	}
 
 	default_pager_convert_to_swapq(object);
 	return (KERN_SUCCESS);
@@ -739,8 +739,9 @@ vm_map_findspace(map, start, length, addr)
 	 * at this address, we have to start after it.
 	 */
 	if (start == map->min_offset) {
-		if ((entry = map->first_free) != &map->header)
+		if ((entry = map->first_free) != &map->header) {
 			start = entry->end;
+		}
 	} else {
 		vm_map_entry_t tmp;
 
@@ -821,12 +822,39 @@ vm_map_find(map, object, offset, addr, length, find_space, prot, max, cow)
 	return (result);
 }
 
+static __pure int
+vm_map_simplify_okay(entry1, entry2)
+	vm_map_entry_t entry1, entry2;
+{
+	if ((entry1->end != entry2->start) ||
+		(entry1->object.vm_object != entry2->object.vm_object))
+		return 0;
+	if (entry1->object.vm_object) {
+		if (entry1->object.vm_object->behavior !=
+			entry2->object.vm_object->behavior)
+			return 0;
+		if (entry1->offset + (entry1->end - entry1->start) !=
+			entry2->offset)
+			return 0;
+	}
+	if ((entry1->needs_copy != entry2->needs_copy) ||
+		(entry1->copy_on_write != entry2->copy_on_write) ||
+		(entry1->protection != entry2->protection) ||
+		(entry1->max_protection != entry2->max_protection) ||
+		(entry1->inheritance != entry2->inheritance) ||
+		(entry1->is_sub_map != FALSE) ||
+		(entry1->is_a_map != FALSE) ||
+		(entry1->wired_count != 0) ||
+		(entry2->is_sub_map != FALSE) ||
+		(entry2->is_a_map != FALSE) ||
+		(entry2->wired_count != 0))
+		return 0;
+
+	return 1;
+}
+	
 /*
  *	vm_map_simplify_entry:	[ internal use only ]
- *
- *	Simplify the given map entry by:
- *		removing extra sharing maps
- *		[XXX maybe later] merging with a neighbor
  */
 static void
 vm_map_simplify_entry(map, entry)
@@ -834,34 +862,13 @@ vm_map_simplify_entry(map, entry)
 	vm_map_entry_t entry;
 {
 	vm_map_entry_t next, prev;
-	vm_size_t nextsize, prevsize, esize;
 
-	/*
-	 * If this entry corresponds to a sharing map, then see if we can
-	 * remove the level of indirection. If it's not a sharing map, then it
-	 * points to a VM object, so see if we can merge with either of our
-	 * neighbors.
-	 */
-
-	if (entry->is_sub_map || entry->is_a_map || entry->wired_count)
+	if (entry->is_a_map || entry->is_sub_map || entry->wired_count)
 		return;
 
 	prev = entry->prev;
 	if (prev != &map->header) {
-		prevsize = prev->end - prev->start;
-		if ( (prev->end == entry->start) &&
-		     (prev->object.vm_object == entry->object.vm_object) &&
-		     (!prev->object.vm_object || (prev->object.vm_object->behavior == entry->object.vm_object->behavior)) &&
-		     (!prev->object.vm_object ||
-			(prev->offset + prevsize == entry->offset)) &&
-		     (prev->needs_copy == entry->needs_copy) &&
-		     (prev->copy_on_write == entry->copy_on_write) &&
-		     (prev->protection == entry->protection) &&
-		     (prev->max_protection == entry->max_protection) &&
-		     (prev->inheritance == entry->inheritance) &&
-		     (prev->is_a_map == FALSE) &&
-		     (prev->is_sub_map == FALSE) &&
-		     (prev->wired_count == 0)) {
+		if ( vm_map_simplify_okay(prev, entry)) {
 			if (map->first_free == prev)
 				map->first_free = entry;
 			if (map->hint == prev)
@@ -877,21 +884,7 @@ vm_map_simplify_entry(map, entry)
 
 	next = entry->next;
 	if (next != &map->header) {
-		nextsize = next->end - next->start;
-		esize = entry->end - entry->start;
-		if ((entry->end == next->start) &&
-		    (next->object.vm_object == entry->object.vm_object) &&
-		    (!next->object.vm_object || (next->object.vm_object->behavior == entry->object.vm_object->behavior)) &&
-		     (!entry->object.vm_object ||
-			(entry->offset + esize == next->offset)) &&
-		    (next->needs_copy == entry->needs_copy) &&
-		    (next->copy_on_write == entry->copy_on_write) &&
-		    (next->protection == entry->protection) &&
-		    (next->max_protection == entry->max_protection) &&
-		    (next->inheritance == entry->inheritance) &&
-		    (next->is_a_map == FALSE) &&
-		    (next->is_sub_map == FALSE) &&
-		    (next->wired_count == 0)) {
+		if ( vm_map_simplify_okay(entry, next)) {
 			if (map->first_free == next)
 				map->first_free = entry;
 			if (map->hint == next)
@@ -904,6 +897,7 @@ vm_map_simplify_entry(map, entry)
 	        }
 	}
 }
+
 /*
  *	vm_map_clip_start:	[ internal use only ]
  *
@@ -1841,6 +1835,21 @@ vm_map_remove(map, start, end)
 }
 
 /*
+ *	vm_map_remove_userspace:
+ *		Removes the user portion of the address space.
+ */
+void
+vm_map_remove_userspace(map)
+	register vm_map_t map;
+{
+	vm_map_lock(map);
+	pmap_remove_pages(map->pmap, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS);
+	vm_map_delete(map, VM_MIN_ADDRESS, VM_MAXUSER_ADDRESS);
+	vm_map_unlock(map);
+	return;
+}
+
+/*
  *	vm_map_check_protection:
  *
  *	Assert that the target map allows the specified
@@ -2257,8 +2266,8 @@ RetryLookup:;
 		lock_write_to_read(&share_map->lock);
 	}
 
-	if (entry->object.vm_object != NULL)
-		default_pager_convert_to_swapq(entry->object.vm_object);
+	default_pager_convert_to_swapq(entry->object.vm_object);
+
 	/*
 	 * Return the object/offset from this entry.  If the entry was
 	 * copy-on-write or empty, it has been fixed up.