config: delete dead ensure_model_parallel_initialized (#39137)

python/sglang/srt/distributed/parallel_state.py

@@ -11,8 +11,7 @@ It takes over the control of the distributed environment from PyTorch.
 The typical workflow is:
 
 - call `init_distributed_environment` to initialize the distributed environment.
-- call `initialize_model_parallel` or `ensure_model_parallel_initialized` to
- initialize the model parallel groups.
+- call `initialize_model_parallel` to initialize the model parallel groups.
 
 - any code dealing with the distributed stuff
 
@@ -2885,46 +2884,6 @@ def create_custom_parallel_group(
     return my_new_group
 
 
-def ensure_model_parallel_initialized(
-    tensor_model_parallel_size: int,
-    expert_model_parallel_size: int,
-    pipeline_model_parallel_size: int,
-    decode_context_parallel_size: int = 1,
-    backend: Optional[str] = None,
-) -> None:
-    """Helper to initialize model parallel groups if they are not initialized,
-    or ensure tensor-parallel and pipeline-parallel sizes are equal to expected
-    values if the model parallel groups are initialized.
-    """
-    backend = backend or torch.distributed.get_backend(get_world_group().device_group)
-    if not model_parallel_is_initialized():
-        initialize_model_parallel(
-            tensor_model_parallel_size=tensor_model_parallel_size,
-            expert_model_parallel_size=expert_model_parallel_size,
-            pipeline_model_parallel_size=pipeline_model_parallel_size,
-            decode_context_parallel_size=decode_context_parallel_size,
-            backend=backend,
-        )
-        return
-
-    assert get_tensor_model_parallel_world_size() == tensor_model_parallel_size, (
-        "tensor parallel group already initialized, but of unexpected size: "
-        f"{get_tensor_model_parallel_world_size()=} vs. "
-        f"{tensor_model_parallel_size=}"
-    )
-    pp_world_size = get_pp_group().world_size
-    assert pp_world_size == pipeline_model_parallel_size, (
-        "pipeline parallel group already initialized, but of unexpected size: "
-        f"{pp_world_size=} vs. "
-        f"{pipeline_model_parallel_size=}"
-    )
-    if decode_context_parallel_size > 1:
-        dcp_world_size = get_dcp_group().world_size
-        assert dcp_world_size == decode_context_parallel_size, (
-            f"decode context parallel group already initialized, but of unexpected size: {dcp_world_size=} {decode_context_parallel_size=}"
-        )
-
-
 def model_parallel_is_initialized():
     """Check if tensor and pipeline parallel groups are initialized."""
     return _TP is not None and _PP is not None