refactor ParallelDescSymbol (#3774)

oneflow/python/eager/boxing_middle.py

@@ -143,7 +143,7 @@ def ReplaceDeviceTag(parallel_desc_symbol, device_tag, builder=None):
         parallel_conf.device_name.append(device_name)
     if builder is None:
         return symbol_util.ParallelDescSymbol(
-            parallel_desc_symbol.symbol_id, parallel_conf, device_tag
+            parallel_desc_symbol.symbol_id, parallel_conf
         )
     else:
         return builder.GetParallelDescSymbol(parallel_conf)
@@ -160,7 +160,7 @@ def RandomParallelIdPerMachine(parallel_desc_symbol, device_tag=None, builder=No
         parallel_conf.device_name.append("%s:%s" % (machine_id, dev_id))
     if builder is None:
         return symbol_util.ParallelDescSymbol(
-            parallel_desc_symbol.symbol_id, parallel_conf, device_tag
+            parallel_desc_symbol.symbol_id, parallel_conf
         )
     else:
         return builder.GetParallelDescSymbol(parallel_conf)

oneflow/python/eager/symbol.py

@@ -34,9 +34,9 @@ class Symbol(object):
 
 
 class ParallelDescSymbol(Symbol):
-    def __init__(self, symbol_id, parallel_conf, device_tag):
+    def __init__(self, symbol_id, parallel_conf):
         Symbol.__init__(self, symbol_id, parallel_conf)
-        self.device_tag_ = device_tag
+        self.device_tag_ = parallel_conf.device_tag
         self.machine_id2device_id_list_ = MakeMachineId2DeviceIdList(parallel_conf)
         sub_parallel_nums = [len(v) for k, v in self.machine_id2device_id_list_.items()]
         self.parallel_num_ = functools.reduce(lambda a, b: a + b, sub_parallel_nums, 0)

oneflow/python/eager/vm_util.py

@@ -421,14 +421,13 @@ class InstructionsBuilder(object):
         return symbol
 
     def GetParallelDescSymbol(self, parallel_conf):
-        device_tag = parallel_conf.device_tag
         serialized_parallel_conf = parallel_conf.SerializeToString()
         if symbol_storage.HasSymbol4SerializedParallelConf(serialized_parallel_conf):
             return symbol_storage.GetSymbol4SerializedParallelConf(
                 serialized_parallel_conf
             )
         symbol_id = self._NewSymbolId4ParallelConf(parallel_conf)
-        symbol = symbol_util.ParallelDescSymbol(symbol_id, parallel_conf, device_tag)
+        symbol = symbol_util.ParallelDescSymbol(symbol_id, parallel_conf)
         symbol_storage.SetSymbol4Id(symbol_id, symbol)
         symbol_storage.SetSymbol4SerializedParallelConf(
             serialized_parallel_conf, symbol