[Hetero] Fix the argument bug (#257)

Co-authored-by: lizhiyu <[email protected]>

megatron/megatron/training/arguments.py

@@ -2184,7 +2184,7 @@ def _add_hetero_args(parser):
     group.add_argument('--hetero-process-meshes', nargs='*', type=int, default=None,
                        help='Use this arg to set TP-CP-DP-PP of each process mesh.'
                        'This argument must be in the form: TP0, CP0, DP0, PP0, TP1, CP0, DP1, PP1...TPN, CPN, DPN, PPN. CP and TP size can be different, sum of PP should match pipeline-model-parallel-size, DP size should be the same.')
-    group.add_argument('--hetero-use-cpu-communication', action='store_true', default=True, help='Use CPU for communication for heterogeneous communication.')
+    group.add_argument('--hetero-use-cpu-communication', action='store_true', help='Use CPU for communication for heterogeneous communication.')
 
     return parser