2017-07-14 38 views
-1

私は1台のマシンの2つのgpuをすべて使用できる自分のmnistの例を書こうとしています。テンソルフローmulti-gpu mnistの例、損失は減少しません

これは単純な多層パーセプトロンです。

ここに私のコードです。直接実行することができます。

from tensorflow.examples.tutorials.mnist import input_data 
mnist = input_data.read_data_sets("/tmp/data/", one_hot=True) 

import tensorflow as tf 

learning_rate = 0.001 
training_steps = 100000 
batch_size = 100 
display_step = 100 

n_hidden_1 = 256 
n_hidden_2 = 256 
n_input = 784 
n_classes = 10 

def _variable_on_cpu(name, shape, initializer): 
    with tf.device('/cpu:0'): 
     dtype = tf.float32 
     var = tf.get_variable(name, shape, initializer=initializer, dtype=dtype) 
    return var 

def build_model(): 

    def multilayer_perceptron(x, weights, biases): 
     layer_1 = tf.add(tf.matmul(x, weights['h1']), biases['b1']) 
     layer_1 = tf.nn.relu(layer_1) 

     layer_2 = tf.add(tf.matmul(layer_1, weights['h2']), biases['b2']) 
     layer_2 = tf.nn.relu(layer_2) 

     out_layer = tf.matmul(layer_2, weights['out']) + biases['out'] 
     return out_layer 

    with tf.variable_scope('aaa'): 
     weights = { 
     'h1': _variable_on_cpu('h1',[n_input, n_hidden_1],tf.constant_initializer(0.0)), 
     'h2': _variable_on_cpu('h2',[n_hidden_1, n_hidden_2],tf.constant_initializer(0.0)), 
     'out': _variable_on_cpu('out_w',[n_hidden_2, n_classes],tf.constant_initializer(0.0)) 
      } 
     biases = { 
     'b1': _variable_on_cpu('b1',[n_hidden_1],tf.constant_initializer(0.0)), 
     'b2': _variable_on_cpu('b2',[n_hidden_2],tf.constant_initializer(0.0)), 
     'out': _variable_on_cpu('out_b',[n_classes],tf.constant_initializer(0.0)) 
      } 

     pred = multilayer_perceptron(x, weights, biases) 

     cost = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(logits=pred, labels=y)) 
    return cost 


def average_gradients(tower_grads): 
    average_grads = [] 
    for grad_and_vars in zip(*tower_grads): 
    grads = [] 
    for g,_ in grad_and_vars: 
     expanded_g = tf.expand_dims(g, 0) 
     grads.append(expanded_g) 
    grad = tf.concat(axis=0, values=grads) 
    grad = tf.reduce_mean(grad, 0) 
    v = grad_and_vars[0][1] 
    grad_and_var = (grad, v) 
    average_grads.append(grad_and_var) 
    return average_grads 


with tf.Graph().as_default(), tf.device('/cpu:0'): 
    x = tf.placeholder("float", [None, n_input]) 
    y = tf.placeholder("float", [None, n_classes]) 
    tower_grads = [] 
    optimizer = tf.train.AdamOptimizer(learning_rate=learning_rate) 
    with tf.variable_scope(tf.get_variable_scope()): 
     for i in xrange(2): 
     with tf.device('/gpu:%d' % i): 
       cost = build_model() 
       tf.get_variable_scope().reuse_variables() 
       grads = optimizer.compute_gradients(cost) 
       tower_grads.append(grads) 

    grads = average_gradients(tower_grads) 
    apply_gradient_op = optimizer.apply_gradients(grads) 
    train_op = apply_gradient_op 

    init = tf.global_variables_initializer() 
    sess = tf.Session() 
    sess.run(init) 

    for step in range(training_steps): 
      image_batch, label_batch = mnist.train.next_batch(batch_size) 
      _, cost_print = sess.run([train_op, cost], 
            {x:image_batch, 
             y:label_batch}) 

      if step % display_step == 0: 
       print("step=%04d" % (step+1)+ " cost=" + str(cost_print)) 
    print("Optimization Finished!") 

    sess.close() 

印刷情報は、次のようになります。

step=0001 cost=2.30258 
step=0101 cost=2.30246 
step=0201 cost=2.30128 
step=0301 cost=2.30376 
step=0401 cost=2.29817 
step=0501 cost=2.2992 
step=0601 cost=2.3104 
step=0701 cost=2.29995 
step=0801 cost=2.29802 
step=0901 cost=2.30524 
step=1001 cost=2.29673 
step=1101 cost=2.30016 
step=1201 cost=2.31057 
step=1301 cost=2.29815 
step=1401 cost=2.29669 
step=1501 cost=2.30345 
step=1601 cost=2.29811 
step=1701 cost=2.30867 
step=1801 cost=2.30757 
step=1901 cost=2.29716 
step=2001 cost=2.30394 

損失が減少しません。私はそれを修正する方法を知らない。

ところで、GPU-Utilは約26%と26%です。どのようにGPU-Utilを増やすのですか?

答えて

0

問題は、私はweights代わりのtf.constant_initializer(0)

ため tf.constant_initializer(0.1)を使用する必要があります

、ということです
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