[hotfix] resharding cost issue (#1742)

Author: YuliangLiu0306

colossalai/auto_parallel/tensor_shard/deprecated/op_handler/where_handler.py

@@ -1,14 +1,21 @@
 import operator
-from functools import reduce
 import warnings
+from copy import deepcopy
+from functools import reduce
+from typing import Dict, List
+
 import torch
+
+from colossalai.auto_parallel.tensor_shard.deprecated._utils import (
+    enumerate_all_possible_1d_sharding,
+    enumerate_all_possible_2d_sharding,
+    exception_handler,
+)
 from colossalai.auto_parallel.tensor_shard.deprecated.sharding_strategy import ShardingStrategy, StrategiesVector
-from .operator_handler import OperatorHandler
 from colossalai.tensor.shape_consistency import ShapeConsistencyManager
 from colossalai.tensor.sharding_spec import ShardingSpec
-from copy import deepcopy
-from typing import Dict, List
-from colossalai.auto_parallel.tensor_shard.deprecated._utils import exception_handler, enumerate_all_possible_1d_sharding, enumerate_all_possible_2d_sharding
+
+from .operator_handler import OperatorHandler
 
 __all__ = ['WhereHandler']
 
@@ -94,7 +101,7 @@ def _generate_resharding_costs(self, sharding_specs):
                 # compute the resharding cost
                 _, _, total_resharding_cost = shape_consistency_manager.shape_consistency(
                     input_sharding_spec, input_spec)
-
+                total_resharding_cost = total_resharding_cost['total']
                 # we need multiply the size of elem dtype to get correct communication cost
                 resharding_cost = total_resharding_cost * size_per_elem_bytes
                 resharding_costs[input_node].append(resharding_cost)