@utils.synchronized(COMPUTE_RESOURCE_SEMAPHORE)
    def drop_move_claim(self, context, instance, instance_type=None,
                        prefix='new_'):
        """Remove usage for an incoming/outgoing migration."""
        if instance['uuid'] in self.tracked_migrations:
            migration, itype = self.tracked_migrations.pop(instance['uuid'])

            if not instance_type:
                ctxt = context.elevated()
                instance_type = self._get_instance_type(ctxt, instance, prefix,
                                                        migration)

            if instance_type is not None and instance_type.id == itype['id']:
                numa_topology = self._get_migration_context_resource(
                    'numa_topology', instance)
                usage = self._get_usage_dict(
                        itype, numa_topology=numa_topology)
                if self.pci_tracker:
                    self.pci_tracker.update_pci_for_migration(context,
                                                              instance,
                                                              sign=-1)
                self._update_usage(usage, sign=-1)

                ctxt = context.elevated()
                self._update(ctxt)

            instance.drop_migration_context()
dataset/ETHPy150Open openstack/nova/nova/compute/resource_tracker.py/ResourceTracker.drop_move_claim/original