张量流中的内存问题

时间:2016-03-04 06:34:27

标签: python tensorflow

我正在尝试使用Tensorflow构建高斯RBM模型。但该程序将使用太多内存。

gaussian_rbm.py

import tensorflow as tf
import math
import input_data
import numpy as np

def sample_prob(probs):
    return tf.nn.relu(
        tf.sign(
            probs - tf.random_uniform(tf.shape(probs))))

class RBM(object):
    """ represents a sigmoidal rbm """

    def __init__(self, name, input_size, output_size, gaussian_std_val=0.1):
        with tf.name_scope("rbm_" + name):
            self.weights = tf.Variable(
                tf.truncated_normal([input_size, output_size],
                    stddev=1.0 / math.sqrt(float(input_size))), name="weights")
            self.v_bias = tf.Variable(tf.zeros([input_size]), name="v_bias")
            self.h_bias = tf.Variable(tf.zeros([output_size]), name="h_bias")
            self.input = tf.placeholder("float", shape=[None, 784])

            #Gaussian
            def_a = 1/(np.sqrt(2)*gaussian_std_val)
            def_a = tf.constant(def_a, dtype=tf.float32)
            self.a = tf.Variable( tf.ones(shape=[input_size]) * def_a,
                                  name="a")


    def propup(self, visible):
        """ P(h|v) """
        return tf.nn.sigmoid(tf.matmul(visible, self.weights) + self.h_bias)

    def propdown(self, hidden):
        """ P(v|h) """
        # return tf.nn.sigmoid(tf.matmul(hidden, tf.transpose(self.weights)) + self.v_bias)
        return ( tf.matmul(hidden, tf.transpose(self.weights)) + self.v_bias ) / (2 * (self.a * self.a))

    def sample_h_given_v(self, v_sample):
        """ Generate a sample from the hidden layer """
        return sample_prob(self.propup(v_sample))

    def sample_v_given_h(self, h_sample):
        """ Generate a sample from the visible layer """
        return self.sample_gaussian(self.propdown(h_sample))

    def gibbs_hvh(self, h0_sample):
        """ A gibbs step starting from the hidden layer """
        v_sample = self.sample_v_given_h(h0_sample)
        h_sample = self.sample_h_given_v(v_sample)
        return [v_sample, h_sample]

    def gibbs_vhv(self, v0_sample):
        """ A gibbs step starting from the visible layer """
        h_sample = self.sample_h_given_v(v0_sample)
        v_sample = self.sample_v_given_h(h_sample)
        return  [h_sample, v_sample]

    def sample_gaussian(self, mean_field):
        return tf.random_normal(shape=tf.shape(mean_field),
                                mean=mean_field,
                                stddev=1.0 / (np.sqrt(2) * self.a))

    def cd1(self, learning_rate=0.1):
        " One step of contrastive divergence, with Rao-Blackwellization "
        h_start = self.sample_h_given_v(self.input)
        v_end = self.sample_v_given_h(h_start)
        h_end = self.sample_h_given_v(v_end)
        w_positive_grad = tf.matmul(tf.transpose(self.input), h_start)
        w_negative_grad = tf.matmul(tf.transpose(v_end), h_end)

        update_w = self.weights + (learning_rate * (w_positive_grad - w_negative_grad) / tf.to_float(tf.shape(self.input)[0]))

        update_vb = self.v_bias + (learning_rate * tf.reduce_mean(self.input - v_end, 0))

        update_hb = self.h_bias + (learning_rate * tf.reduce_mean(h_start - h_end, 0))

        return [update_w, update_vb, update_hb]

    def cal_err(self):
        err = self.input - self.gibbs_vhv(self.input)[1]
        return tf.reduce_mean(err * err)

test_mnist.py

import tensorflow as tf
import input_data
from gaussian_RBM import RBM

mnist = input_data.read_data_sets("MNIST_data/", one_hot=True)
trX, trY, teX, teY = mnist.train.images, mnist.train.labels, mnist.test.images, mnist.test.labels

rbm_modle = RBM(name="gaussian_rbm", input_size=784, output_size=1000)

sess = tf.Session()
init_op = tf.initialize_all_variables()
sess.run(init_op)

for i in range(100):
    print "step: %s"%i
    for start, end in zip(range(0, len(trX), 128), range(128, len(trX), 128)):

        rbm_modle.weights, rbm_modle.v_bias, rbm_modle.h_bias = \
            sess.run(rbm_modle.cd1(), feed_dict={rbm_modle.input : trX[start : end]})

        if start % 1280 == 0:
            print sess.run(rbm_modle.cal_err(), feed_dict={rbm_modle.input : teX})

输出

  

运行test_mnist.py提取MNIST_data / train-images-idx3-ubyte.gz   提取MNIST_data / train-labels-idx1-ubyte.gz提取   MNIST_data / t10k-images-idx3-ubyte.gz提取   MNIST_data / t10k-labels-idx1-ubyte.gz I   tensorflow / stream_executor / cuda / cuda_gpu_executor.cc:900]成功   从SysFS读取的NUMA节点具有负值(-1),但必须存在   至少有一个NUMA节点,因此返回NUMA节点为零   tensorflow / core / common_runtime / gpu / gpu_init.cc:102]找到设备0   具有属性:名称:GeForce GTX 560主要:2个未成年人:1   memoryClockRate(GHz)1.62 pciBusID 0000:01:00.0总内存:   1018.69MiB可用内存:916.73MiB I tensorflow / core / common_runtime / gpu / gpu_init.cc:126] DMA:0 I   tensorflow / core / common_runtime / gpu / gpu_init.cc:136] 0:是的我   tensorflow / core / common_runtime / gpu / gpu_device.cc:684]忽略gpu   设备(设备:0,名称:GeForce GTX 560,pci总线ID:0000:01:00.0)   具有Cuda计算能力2.1。最低要求的Cuda能力   是3.5。步骤:0   0.0911714   0.0781856   0.0773076   0.0770751   0.0776582   0.0764748   0.0755164   0.0741131   0.0726497   0.0712237   0.0701839   0.0686315   0.0664856   0.0658309   0.0646239   0.0626652   0.0616178   0.0610061   0.0598332   0.0588843   0.0587477   0.0572056   0.0561556   0.0554848已被杀害

有没有办法监控内存? 有人能帮助我吗?

4 个答案:

答案 0 :(得分:5)

您可以使用命令nvidia-smi

监视GPU内存

看起来您的GPU不支持运行tensorflow所需的更高版本的CUDA。您可以查看CUDA-Enabled GeForce Products

从你的输出看,tensorflow看起来很聪明,不能使用GPU,因此你的模型/批量大小对于你的RAM来说太大或你有内存泄漏。

尝试使用log_device_placement = True运行正在运行的会话以查看tensorflow正在逐步执行的操作,同时运行' top'监控记忆?

    with tf.Session(config=tf.ConfigProto(log_device_placement=True)) as sess:

答案 1 :(得分:2)

训练循环可能存在问题,导致计算机内存不足。

对于循环的每次迭代,您都在调用:

sess.run(rbm_modle.cd1(), feed_dict={rbm_modle.input : trX[start : end]})

在此rbm_modle.cd1()函数中,您正在创建几个新操作,例如tf.matmul(),因此每次调用rbm_modle.cd1()时,您都将创建新操作,这将导致已用内存每次迭代后都会增加。

您应该在循环之前定义所有操作,然后在使用sess.run()运行操作期间,而不创建新的操作。

答案 2 :(得分:0)

答案似乎是正确的,(运行最新版本的CUDA / Tensorflow的计算能力不足

然而,最低要求似乎是“Compute Capabilites = 3.0”,因为我的GTX_770M能够运行Tensorflow 1.0 / CUDA 8.0(见下文)

和/或尝试从源代码重新编译tensorflow,并在生成期间包含2.0目标(默认情况下建议使用3.5-5.5)

祝你有个美好的一天!!

+-----------------------------------------------------------------------------+
| NVIDIA-SMI 375.51                 Driver Version: 375.51                    |
|-------------------------------+----------------------+----------------------+
| 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 770M    Off  | 0000:01:00.0     N/A |                  N/A |
|100%   48C    P0    N/A /  N/A |   2819MiB /  3017MiB |     N/A      Default |
+-------------------------------+----------------------+----------------------+

+-----------------------------------------------------------------------------+
| Processes:                                                       GPU Memory |
|  GPU       PID  Type  Process name                               Usage      |
|=============================================================================|
|    0                  Not Supported                                         |
+-----------------------------------------------------------------------------+

答案 3 :(得分:0)

在使用

进行培训之前,通过使图表为只读,确保没有内存泄漏
tf.get_default_graph().finalize()

每次尝试添加新节点时,TensorFlow都会引发异常。