[Misc] update doc comment for send (#22026)

Signed-off-by: Andy Xie <andy.xning@gmail.com>

vllm/distributed/device_communicators/base_device_communicator.py

@@ -219,7 +219,7 @@ class DeviceCommunicatorBase:
         return output_tensor
 
     def send(self, tensor: torch.Tensor, dst: Optional[int] = None) -> None:
-        """Sends a tensor to the destination rank in a non-blocking way"""
+        """Sends a tensor to the destination rank in a blocking way"""
         """NOTE: `dst` is the local rank of the destination rank."""
         if dst is None:
             dst = (self.rank_in_group + 1) % self.world_size

vllm/distributed/device_communicators/cuda_communicator.py

@@ -179,7 +179,7 @@ class CudaCommunicator(DeviceCommunicatorBase):
         return output.movedim(0, dim).contiguous()
 
     def send(self, tensor: torch.Tensor, dst: Optional[int] = None) -> None:
-        """Sends a tensor to the destination rank in a non-blocking way"""
+        """Sends a tensor to the destination rank in a blocking way"""
         """NOTE: `dst` is the local rank of the destination rank."""
         if dst is None:
             dst = (self.rank_in_group + 1) % self.world_size

vllm/distributed/parallel_state.py

@@ -782,7 +782,7 @@ class GroupCoordinator:
         torch.distributed.barrier(group=self.cpu_group)
 
     def send(self, tensor: torch.Tensor, dst: Optional[int] = None) -> None:
-        """Sends a tensor to the destination rank in a non-blocking way"""
+        """Sends a tensor to the destination rank in a blocking way"""
         """NOTE: `dst` is the local rank of the destination rank."""
         self.device_communicator.send(tensor, dst)