rewrite_options->mutable_scoped_allocator_opts()->add_enable_op(
      "CollectiveReduce");

  if ((tensorflow::IsGoogleCudaEnabled() || tensorflow::IsBuiltWithROCm()) &&
      num_virtual_gpus > 0) {
    tensorflow::GPUOptions* gpu_options =
        server_def.mutable_default_session_config()->mutable_gpu_options();
    auto virtual_devices =
        gpu_options->mutable_experimental()->add_virtual_devices();