问找不到为什么Tensorflow-GPU不使用我的GPU，以及为什么它显示N instaed of Y作为输出

EN

(tfenv) hobbes@hobbes-HP-Pavilion-Notebook:~/tfenv$ python
Python 3.6.5 (default, Apr  1 2018, 05:46:30) 
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import tensorflow as tf
/home/hobbes/tfenv/lib/python3.6/site-packages/h5py/__init__.py:36: FutureWarning: Conversion of the second argument of issubdtype from `float` to `np.floating` is deprecated. In future, it will be treated as `np.float64 == np.dtype(float).type`.
  from ._conv import register_converters as _register_converters
>>> with tf.device('/gpu:0'):
...     a = tf.constant([1.0, 2.0, 3.0, 4.0, 5.0, 6.0], shape=[2, 3], name='a')
...     b = tf.constant([1.0, 2.0, 3.0, 4.0, 5.0, 6.0], shape=[3, 2], name='b')
...     c = tf.matmul(a, b)
... 
>>> with tf.Session() as sess:
...     print (sess.run(c))
... 
2018-05-26 17:39:53.860779: I tensorflow/core/platform/cpu_feature_guard.cc:140] Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX2 FMA
2018-05-26 17:39:53.946021: I tensorflow/stream_executor/cuda/cuda_gpu_executor.cc:898] successful NUMA node read from SysFS had negative value (-1), but there must be at least one NUMA node, so returning NUMA node zero
2018-05-26 17:39:53.946434: I tensorflow/core/common_runtime/gpu/gpu_device.cc:1356] Found device 0 with properties: 
name: GeForce GTX 960M major: 5 minor: 0 memoryClockRate(GHz): 1.176
pciBusID: 0000:01:00.0
totalMemory: 1.96GiB freeMemory: 1.66GiB
2018-05-26 17:39:53.946450: I tensorflow/core/common_runtime/gpu/gpu_device.cc:1435] Adding visible gpu devices: 0
2018-05-26 17:39:54.449040: I tensorflow/core/common_runtime/gpu/gpu_device.cc:923] Device interconnect StreamExecutor with strength 1 edge matrix:
2018-05-26 17:39:54.449064: I tensorflow/core/common_runtime/gpu/gpu_device.cc:929]      0 
2018-05-26 17:39:54.449070: I tensorflow/core/common_runtime/gpu/gpu_device.cc:942] 0:   N 
2018-05-26 17:39:54.449194: I tensorflow/core/common_runtime/gpu/gpu_device.cc:1053] Created TensorFlow device (/job:localhost/replica:0/task:0/device:GPU:0 with 1416 MB memory) -> physical GPU (device: 0, name: GeForce GTX 960M, pci bus id: 0000:01:00.0, compute capability: 5.0)
[[22. 28.]
 [49. 64.]]

<pre><font color="#8AE234"><b>hobbes@hobbes-HP-Pavilion-Notebook</b></font>:<font color="#729FCF"><b>~</b></font>$ nvidia-smi
Sat May 26 18:23:59 2018       
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 396.24                 Driver Version: 396.24                    |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|===============================+======================+======================|
|   0  GeForce GTX 960M    Off  | 00000000:01:00.0 Off |                  N/A |
| N/A   55C    P8    N/A /  N/A |    267MiB /  2002MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
                                                                               
+-----------------------------------------------------------------------------+
| Processes:                                                       GPU Memory |
|  GPU       PID   Type   Process name                             Usage      |
|=============================================================================|
|    0      1286      G   /usr/lib/xorg/Xorg                            24MiB |
|    0      1464      G   /usr/bin/gnome-shell                          48MiB |
|    0      1650      G   /usr/lib/xorg/Xorg                           103MiB |
|    0      1820      G   /usr/bin/gnome-shell                          87MiB |
+-----------------------------------------------------------------------------+
<font color="#8AE234"><b>hobbes@hobbes-HP-Pavilion-Notebook</b></font>:<font color="#729FCF"><b>~</b></font>$ 

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