Updates to a given inventory should happen serially

awx/main/management/commands/inventory_import.py

@@ -874,7 +874,6 @@ class Command(BaseCommand):
         Load inventory from in-memory groups to the database, overwriting or
         merging as appropriate.
         '''
-        with advisory_lock('inventory_{}_update'.format(self.inventory.id)):
         # FIXME: Attribute changes to superuser?
         # Perform __in queries in batches (mainly for unit tests using SQLite).
         self._batch_size = 500
@@ -998,6 +997,7 @@ class Command(BaseCommand):
             raise CommandError('invalid regular expression for --host-filter')
 
         begin = time.time()
+        with advisory_lock('inventory_{}_update'.format(self.inventory_id)):
             self.load_inventory_from_database()
 
             try: