Tensorflow doesn't show "Successfully opened so called CUDA libraries locally"

I configured tensorflow to work with CUDA support on my GPU (GeForce 840M), but the programs are quite slow compared to what my processor used before. Also, I am not getting any message that was such that the CUDA library was successfully opened when the program was started. Instead, this is what I get in the logs when I run any tensorflow program:

python Neuralnet.py 
Successfully downloaded train-images-idx3-ubyte.gz 9912422 bytes.
Extracting /tmp/data/train-images-idx3-ubyte.gz
Successfully downloaded train-labels-idx1-ubyte.gz 28881 bytes.
Extracting /tmp/data/train-labels-idx1-ubyte.gz
Successfully downloaded t10k-images-idx3-ubyte.gz 1648877 bytes.
Extracting /tmp/data/t10k-images-idx3-ubyte.gz
Successfully downloaded t10k-labels-idx1-ubyte.gz 4542 bytes.
Extracting /tmp/data/t10k-labels-idx1-ubyte.gz
2017-03-28 07:53:57.979382: W tensorflow/core/platform/cpu_feature_guard.cc:45]
    The TensorFlow library wasn't compiled to use SSE4.1 instructions, 
    but these are available on your machine and could speed up CPU computations.
2017-03-28 07:53:57.979413: W tensorflow/core/platform/cpu_feature_guard.cc:45]
    The TensorFlow library wasn't compiled to use SSE4.2 instructions, 
    but these are available on your machine and could speed up CPU computations.
2017-03-28 07:53:57.979431: W tensorflow/core/platform/cpu_feature_guard.cc:45] 
    The TensorFlow library wasn't compiled to use AVX instructions, 
    but these are available on your machine and could speed up CPU computations.
2017-03-28 07:53:57.979438: W tensorflow/core/platform/cpu_feature_guard.cc:45] 
    The TensorFlow library wasn't compiled to use AVX2 instructions, 
    but these are available on your machine and could speed up CPU computations.
2017-03-28 07:53:57.979447: W tensorflow/core/platform/cpu_feature_guard.cc:45] 
    The TensorFlow library wasn't compiled to use FMA instructions, 
    but these are available on your machine and could speed up CPU computations.
2017-03-28 07:53:58.233876: I tensorflow/stream_executor/cuda/cuda_gpu_executor.cc:901] 
    successful NUMA node read from SysFS had negative value (-1),
    but there must be at least one NUMA node, so returning NUMA node zero
2017-03-28 07:53:58.234333: I tensorflow/core/common_runtime/gpu/gpu_device.cc:887] 
Found device 0 with properties: 
name: GeForce 840M
major: 5 minor: 0 memoryClockRate (GHz) 1.124
pciBusID 0000:08:00.0
Total memory: 1.96GiB
Free memory: 1.75GiB
2017-03-28 07:53:58.234362: I tensorflow/core/common_runtime/gpu/gpu_device.cc:908] DMA: 0 
2017-03-28 07:53:58.234372: I tensorflow/core/common_runtime/gpu/gpu_device.cc:918] 0:   Y 
2017-03-28 07:53:58.234388: I tensorflow/core/common_runtime/gpu/gpu_device.cc:977] 
Creating TensorFlow device (/gpu:0) -> (device: 0, name: GeForce 840M, pci bus id: 0000:08:00.0)
('Epoch', 0, 'completed out of', 15, 'loss:', 115374329.04653475)

      

        
        
        
      

    

So, the program started to work, but according to my expectations, it did not work faster. I installed CUDA from the official documentation, but I didn’t reset the git head as it was causing problems and I used the same optimization flags I did bazel build -c opt --config=cuda //tensorflow/tools/pip_package:build_pip_package

when building via bazel.