svn commit: r215469 - head/sys/vm

[Konstantin Belousov]

Author: kib
Date: Thu Nov 18 20:46:28 2010
New Revision: 215469
URL: http://svn.freebsd.org/changeset/base/215469

Log:
  Only increment object generation count when inserting the page into
  object page list.  The only use of object generation count now is a
  restart of the scan in vm_object_page_clean(), which makes sense to do
  on the page addition. Page removals do not affect the dirtiness of the
  object, as well as manipulations with the shadow chain.
  
  Suggested and reviewed by:	alc
  MFC after:    1 week

Modified:
  head/sys/vm/vm_object.c
  head/sys/vm/vm_page.c

Modified: head/sys/vm/vm_object.c
==============================================================================
--- head/sys/vm/vm_object.c	Thu Nov 18 19:28:45 2010	(r215468)
+++ head/sys/vm/vm_object.c	Thu Nov 18 20:46:28 2010	(r215469)
@@ -600,7 +600,6 @@ doterm:
 			VM_OBJECT_LOCK(temp);
 			LIST_REMOVE(object, shadow_list);
 			temp->shadow_count--;
-			temp->generation++;
 			VM_OBJECT_UNLOCK(temp);
 			object->backing_object = NULL;
 		}
@@ -1192,7 +1191,6 @@ vm_object_shadow(
 		VM_OBJECT_LOCK(source);
 		LIST_INSERT_HEAD(&source->shadow_head, result, shadow_list);
 		source->shadow_count++;
-		source->generation++;
 #if VM_NRESERVLEVEL > 0
 		result->flags |= source->flags & OBJ_COLORED;
 		result->pg_color = (source->pg_color + OFF_TO_IDX(*offset)) &
@@ -1260,7 +1258,6 @@ vm_object_split(vm_map_entry_t entry)
 		LIST_INSERT_HEAD(&source->shadow_head,
 				  new_object, shadow_list);
 		source->shadow_count++;
-		source->generation++;
 		vm_object_reference_locked(source);	/* for new_object */
 		vm_object_clear_flag(source, OBJ_ONEMAPPING);
 		VM_OBJECT_UNLOCK(source);
@@ -1651,7 +1648,6 @@ vm_object_collapse(vm_object_t object)
 			 */
 			LIST_REMOVE(object, shadow_list);
 			backing_object->shadow_count--;
-			backing_object->generation++;
 			if (backing_object->backing_object) {
 				VM_OBJECT_LOCK(backing_object->backing_object);
 				LIST_REMOVE(backing_object, shadow_list);
@@ -1661,7 +1657,6 @@ vm_object_collapse(vm_object_t object)
 				/*
 				 * The shadow_count has not changed.
 				 */
-				backing_object->backing_object->generation++;
 				VM_OBJECT_UNLOCK(backing_object->backing_object);
 			}
 			object->backing_object = backing_object->backing_object;
@@ -1703,7 +1698,6 @@ vm_object_collapse(vm_object_t object)
 			 */
 			LIST_REMOVE(object, shadow_list);
 			backing_object->shadow_count--;
-			backing_object->generation++;
 
 			new_backing_object = backing_object->backing_object;
 			if ((object->backing_object = new_backing_object) != NULL) {
@@ -1714,7 +1708,6 @@ vm_object_collapse(vm_object_t object)
 				    shadow_list
 				);
 				new_backing_object->shadow_count++;
-				new_backing_object->generation++;
 				vm_object_reference_locked(new_backing_object);
 				VM_OBJECT_UNLOCK(new_backing_object);
 				object->backing_object_offset +=

Modified: head/sys/vm/vm_page.c
==============================================================================
--- head/sys/vm/vm_page.c	Thu Nov 18 19:28:45 2010	(r215468)
+++ head/sys/vm/vm_page.c	Thu Nov 18 20:46:28 2010	(r215469)
@@ -846,7 +846,6 @@ vm_page_remove(vm_page_t m)
 	 * And show that the object has one fewer resident page.
 	 */
 	object->resident_page_count--;
-	object->generation++;
 	/*
 	 * The vnode may now be recycled.
 	 */
@@ -1983,7 +1982,6 @@ vm_page_cache(vm_page_t m)
 	object->root = root;
 	TAILQ_REMOVE(&object->memq, m, listq);
 	object->resident_page_count--;
-	object->generation++;
 
 	/*
 	 * Restore the default memory attribute to the page.
@@ -2395,7 +2393,6 @@ vm_page_set_invalid(vm_page_t m, int bas
 	    ("vm_page_set_invalid: page %p is mapped", m));
 	m->valid &= ~bits;
 	m->dirty &= ~bits;
-	m->object->generation++;
 }
 
 /*