class_docstr: All-reduce the input from the model parallel region.
  
  Args:
      input_: input matrix.
      parallel_mode: parallel mode.
class_docstr_tok: ["All-reduce","the","input","from","the","model","parallel","region",".","Args",":","input_",":","input","matrix",".","parallel_mode",":","parallel","mode","."]
code: def backward(ctx, grad_output):
      return grad_output, None
  
imports: import torch
  import torch.distributed
  import torch.nn.functional
label_desc: Use image node_id 2 for calling the _ReduceForward obj's underlying member method code with example usage: obj.backward(ctx, grad_output) and returns: grad_output,  None