Reintroduce locking on accesses to vm_object_list.

3 files changed, 10 insertions, 1 deletions

diff --git a/sys/vm/vm_meter.c b/sys/vm/vm_meter.c
index fde1f49..935979ae 100644
--- a/sys/vm/vm_meter.c
+++ b/sys/vm/vm_meter.c
@@ -95,8 +95,10 @@ vmtotal(SYSCTL_HANDLER_ARGS)
 	 * Mark all objects as inactive.
 	 */
 	GIANT_REQUIRED;
+	mtx_lock(&vm_object_list_mtx);
 	TAILQ_FOREACH(object, &vm_object_list, object_list)
 		vm_object_clear_flag(object, OBJ_ACTIVE);
+	mtx_unlock(&vm_object_list_mtx);
 	/*
 	 * Calculate process statistics.
 	 */
@@ -164,6 +166,7 @@ vmtotal(SYSCTL_HANDLER_ARGS)
 	/*
 	 * Calculate object memory usage statistics.
 	 */
+	mtx_lock(&vm_object_list_mtx);
 	TAILQ_FOREACH(object, &vm_object_list, object_list) {
 		/*
 		 * devices, like /dev/mem, will badly skew our totals
@@ -186,6 +189,7 @@ vmtotal(SYSCTL_HANDLER_ARGS)
 			}
 		}
 	}
+	mtx_unlock(&vm_object_list_mtx);
 	totalp->t_free = cnt.v_free_count + cnt.v_cache_count;
 	return (sysctl_handle_opaque(oidp, totalp, sizeof total, req));
 }
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index 37c329d..5d13cac 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -137,7 +137,7 @@ static int	vm_object_page_collect_flush(vm_object_t object, vm_page_t p, int cur
  */
 
 struct object_q vm_object_list;
-static struct mtx vm_object_list_mtx;	/* lock for object list and count */
+struct mtx vm_object_list_mtx;	/* lock for object list and count */
 vm_object_t kernel_object;
 vm_object_t kmem_object;
 static struct vm_object kernel_object_store;
@@ -222,7 +222,9 @@ _vm_object_allocate(objtype_t type, vm_size_t size, vm_object_t object)
 
 	object->generation++;
 
+	mtx_lock(&vm_object_list_mtx);
 	TAILQ_INSERT_TAIL(&vm_object_list, object, object_list);
+	mtx_unlock(&vm_object_list_mtx);
 
 	object_hash_rand = object->hash_rand;
 }
@@ -1511,11 +1513,13 @@ vm_object_collapse(vm_object_t object)
 			KASSERT(backing_object->ref_count == 1, ("backing_object %p was somehow re-referenced during collapse!", backing_object));
 			KASSERT(TAILQ_FIRST(&backing_object->memq) == NULL, ("backing_object %p somehow has left over pages during collapse!", backing_object));
 
+			mtx_lock(&vm_object_list_mtx);
 			TAILQ_REMOVE(
 			    &vm_object_list, 
 			    backing_object,
 			    object_list
 			);
+			mtx_unlock(&vm_object_list_mtx);
 
 			uma_zfree(obj_zone, backing_object);
 
diff --git a/sys/vm/vm_object.h b/sys/vm/vm_object.h
index 1256e85..62244a9 100644
--- a/sys/vm/vm_object.h
+++ b/sys/vm/vm_object.h
@@ -160,6 +160,7 @@ struct vm_object {
 TAILQ_HEAD(object_q, vm_object);
 
 extern struct object_q vm_object_list;	/* list of allocated objects */
+extern struct mtx vm_object_list_mtx;	/* lock for object list and count */
 
 extern vm_object_t kernel_object;	/* the single kernel object */
 extern vm_object_t kmem_object;