TensorFlow c++ SetDefaultDevice 在多 GPU 模式下

我想在多个GPU上加载相同的图形以进行推理，但是我无法使用graph：：SetDefaultDevice将图形与设备相关联。 此问题不是在 SetDefaultDevice 中发生，而是在稍后使用图形创建会话时发生。这是一个从张量流的 example_trainer.cc 中提取的简单示例

#include <tensorflow/core/platform/env.h>
#include <tensorflow/core/public/session.h>
#include "tensorflow/cc/ops/standard_ops.h"
#include "tensorflow/core/graph/default_device.h"
int main() {
using namespace tensorflow;
using namespace tensorflow::ops;
Scope root = Scope::NewRootScope();
auto A = Const(root, { {3.f, 2.f}, {-1.f, 0.f} }); 
auto b = Const(root, { {3.f, 5.f} }); 
auto v = MatMul(root.WithOpName("v"), A, b, MatMul::TransposeB(true));
GraphDef def;
TF_CHECK_OK(root.ToGraphDef(&def));
graph::SetDefaultDevice(false ? "/device:GPU:0" : "/cpu:0", &def);
/*
for (auto &node: *def.mutable_node()) {
node.set_device("/cpu:0");
std::cout << node.name() << " = '" << node.device() <<"'"<< std::endl;
}
std::cout << "=======================n";
*/
SessionOptions options;
std::unique_ptr<Session> session(NewSession(options));
TF_CHECK_OK(session->Create(def));
return 0;
}

运行时出现以下错误

2018-09-06 18:18:13.853316: I tensorflow/core/platform/cpu_feature_guard.cc:141] Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX2 FMA
2018-09-06 18:18:13.856079: F /home/daniel/tensorflow_cc/example/example.cpp:27] Non-OK-status: session->Create(def) status: Not found: No attr named '/cpu:0' in NodeDef:
[[Node: Const = Const[dtype=DT_FLOAT, value=Tensor<type: float shape: [2,2] values: [3 2][-1]...>, _device="/cpu:0"]()]]
[[Node: Const = Const[dtype=DT_FLOAT, value=Tensor<type: float shape: [2,2] values: [3 2][-1]...>, _device="/cpu:0"]()]]
Aborted (core dumped)

如果我删除 SetDefault 设备调用，它可以完美运行。我也尝试在带有GPU的机器上执行此操作，但它不起作用。

我知道问题不在于 SetDefaultDevice，因为手动设置每个节点的设备在创建会话时会遇到相同的问题。

Const = '/cpu:0'
Const_1 = '/cpu:0'
v = '/cpu:0'
=======================
2018-09-06 18:15:05.966337: I tensorflow/core/platform/cpu_feature_guard.cc:141] Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX2 FMA
2018-09-06 18:15:05.969048: F /home/daniel/tensorflow_cc/example/example.cpp:26] Non-OK-status: session->Create(def) status: Not found: No attr named '/cpu:0' in NodeDef:
[[Node: Const = Const[dtype=DT_FLOAT, value=Tensor<type: float shape: [2,2] values: [3 2][-1]...>, _device="/cpu:0"]()]]
[[Node: Const = Const[dtype=DT_FLOAT, value=Tensor<type: float shape: [2,2] values: [3 2][-1]...>, _device="/cpu:0"]()]]
Aborted (core dumped)