title: tensorflow tf.initializeallvariables() taking too much time even while init with few variables
body: <p>Tensorflow is taking too much time to run the tf.initializeallvariables() routine for some reason. I am using cuda 8.0 with NVIDIA TitanX Pascal and latest tensorflow. I am not sure about the reason and would appreciate any help. </p>
  
  <pre><code>import tensorflow as tf
  import numpy as np
  
  cls = np.zeros((5, 10))
  classes = tf.Variable(cls, dtype=tf.float32)
  
  config = tf.ConfigProto()
  config.gpu_options.allow_growth = True
  sess = tf.InteractiveSession(config=config)
  sess.run(tf.initialize_all_variables())
  </code></pre>