[distributed] remove pynccl's redundant change_state (#11749)

vllm/distributed/device_communicators/pynccl.py

@@ -1,4 +1,3 @@
-from contextlib import contextmanager
 from typing import Optional, Union
 
 # ===================== import region =====================
@@ -213,19 +212,3 @@ class PyNcclCommunicator:
         self.nccl.ncclBroadcast(sendbuff, recvbuff, tensor.numel(),
                                 ncclDataTypeEnum.from_torch(tensor.dtype), src,
                                 self.comm, cudaStream_t(stream.cuda_stream))
-
-    @contextmanager
-    def change_state(self, enable: Optional[bool] = None):
-        """
-        A context manager to change the state of the communicator.
-        """
-        if enable is None:
-            # guess a default value when not specified
-            enable = self.available
-
-        old_disable = self.disabled
-
-        self.disabled = not enable
-        yield
-
-        self.disabled = old_disable

vllm/distributed/parallel_state.py

@@ -305,14 +305,7 @@ class GroupCoordinator:
             stream.wait_stream(curr_stream)
 
         with torch.cuda.stream(stream), maybe_ca_context:
-            pynccl_comm = self.pynccl_comm
-            maybe_pynccl_context: Any
-            if not pynccl_comm:
-                maybe_pynccl_context = nullcontext()
-            else:
-                maybe_pynccl_context = pynccl_comm.change_state()
-            with maybe_pynccl_context:
-                yield graph_capture_context
+            yield graph_capture_context
 
     def all_reduce(self, input_: torch.Tensor) -> torch.Tensor:
         """