Removed assert in case of external ddp, exported initialize_megatron()

Signed-off-by: Boris Fomitchev <bfomitchev@nvidia.com>

megatron/__init__.py

@@ -30,7 +30,7 @@ from .global_vars import get_tokenizer
 from .global_vars import get_tensorboard_writer
 from .global_vars import get_adlr_autoresume
 from .global_vars import get_timers
-
+from .initialize  import initialize_megatron
 
 def print_rank_0(message):
     """If distributed is initialized print only on rank 0."""

megatron/initialize.py

@@ -93,11 +93,6 @@ def _initialize_distributed():
                   'skipping initialization ...', flush=True)
         args.rank = torch.distributed.get_rank()
         args.world_size = torch.distributed.get_world_size()
-        if device_count > 0:
-            device = torch.cuda.current_device()
-            local_rank = args.rank % device_count
-            assert local_rank == device, \
-                'expected local-rank to be the same as rank % device-count.'
 
     else: