title: Error using Tensorflow with GPU
body: <p>I've tried a bunch of different Tensorflow examples, which works fine on the CPU but generates the same error when I'm trying to run them on the GPU. One little example is this:</p>
  
  <pre><code>import tensorflow as tf
  
  # Creates a graph.
  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)
  # Creates a session with log_device_placement set to True.
  sess = tf.Session(config=tf.ConfigProto(log_device_placement=True))
  # Runs the op.
  print sess.run(c)
  </code></pre>
  
  <p>The error is always the same, CUDA_ERROR_OUT_OF_MEMORY:</p>
  
  <pre><code>I tensorflow/stream_executor/dso_loader.cc:101] successfully opened CUDA library libcublas.so.7.0 locally
  I tensorflow/stream_executor/dso_loader.cc:101] successfully opened CUDA library libcudnn.so.6.5 locally
  I tensorflow/stream_executor/dso_loader.cc:101] successfully opened CUDA library libcufft.so.7.0 locally
  I tensorflow/stream_executor/dso_loader.cc:101] successfully opened CUDA library libcuda.so locally
  I tensorflow/stream_executor/dso_loader.cc:101] successfully opened CUDA library libcurand.so.7.0 locally
  I tensorflow/core/common_runtime/local_device.cc:40] Local device intra op parallelism threads: 24
  I tensorflow/core/common_runtime/gpu/gpu_init.cc:103] Found device 0 with properties: 
  name: Tesla K80
  major: 3 minor: 7 memoryClockRate (GHz) 0.8235
  pciBusID 0000:0a:00.0
  Total memory: 11.25GiB
  Free memory: 105.73MiB
  I tensorflow/core/common_runtime/gpu/gpu_init.cc:103] Found device 1 with properties: 
  name: Tesla K80
  major: 3 minor: 7 memoryClockRate (GHz) 0.8235
  pciBusID 0000:0b:00.0
  Total memory: 11.25GiB
  Free memory: 133.48MiB
  I tensorflow/core/common_runtime/gpu/gpu_init.cc:127] DMA: 0 1 
  I tensorflow/core/common_runtime/gpu/gpu_init.cc:137] 0:   Y Y 
  I tensorflow/core/common_runtime/gpu/gpu_init.cc:137] 1:   Y Y 
  I tensorflow/core/common_runtime/gpu/gpu_device.cc:702] Creating TensorFlow device (/gpu:0) -&gt; (device: 0, name: Tesla K80, pci bus id: 0000:0a:00.0)
  I tensorflow/core/common_runtime/gpu/gpu_device.cc:702] Creating TensorFlow device (/gpu:1) -&gt; (device: 1, name: Tesla K80, pci bus id: 0000:0b:00.0)
  I tensorflow/core/common_runtime/gpu/gpu_bfc_allocator.cc:42] Allocating 105.48MiB bytes.
  E tensorflow/stream_executor/cuda/cuda_driver.cc:932] failed to allocate 105.48M (110608384 bytes) from device: CUDA_ERROR_OUT_OF_MEMORY
  F tensorflow/core/common_runtime/gpu/gpu_bfc_allocator.cc:47] Check failed: gpu_mem != nullptr  Could not allocate GPU device memory for device 0. Tried to allocate 105.48MiB
  Aborted (core dumped)
  </code></pre>
  
  <p>I guess that the problem has to do with my configuration rather than the memory usage of this tiny example. Does anyone have any idea? </p>
  
  <p><strong>Edit:</strong></p>
  
  <p>I've found out that the problem may be as simple as someone else running a job on the same GPU, which would explain the little amount of free memory. In that case: sorry for taking up your time...</p>