Add a new option, OBJPR_NOTMAPPED, to vm_object_page_remove(). Passing this

option to vm_object_page_remove() asserts that the specified range of pages
is not mapped, or more precisely that none of these pages have any managed
mappings.  Thus, vm_object_page_remove() need not call pmap_remove_all() on
the pages.

This change not only saves time by eliminating pointless calls to
pmap_remove_all(), but it also eliminates an inconsistency in the use of
pmap_remove_all() versus related functions, like pmap_remove_write().  It
eliminates harmless but pointless calls to pmap_remove_all() that were being
performed on PG_UNMANAGED pages.

Update all of the existing assertions on pmap_remove_all() to reflect this
change.

Reviewed by:	kib

1 files changed, 9 insertions, 1 deletions

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 752354a..31886af 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -2708,7 +2708,15 @@ vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
 		    ((object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) == OBJ_ONEMAPPING ||
 		    object == kernel_object || object == kmem_object)) {
 			vm_object_collapse(object);
-			vm_object_page_remove(object, offidxstart, offidxend, FALSE);
+
+			/*
+			 * The option OBJPR_NOTMAPPED can be passed here
+			 * because vm_map_delete() already performed
+			 * pmap_remove() on the only mapping to this range
+			 * of pages. 
+			 */
+			vm_object_page_remove(object, offidxstart, offidxend,
+			    OBJPR_NOTMAPPED);
 			if (object->type == OBJT_SWAP)
 				swap_pager_freespace(object, offidxstart, count);
 			if (offidxend >= object->size &&