我将强化学习与神经网络 (DQN) 结合使用。我有一台配备 6 核 i7 和 AMD GPU 的 MacBook。TensorFlow 看不到 GPU,因此它会自动使用 CPU。当我运行脚本时,我在活动监视器中看到 CPU 利用率从大约 33% 变为 ~50%,即没有使用所有 CPU 内核。我的 TensorFlow 版本是 2.2.0。我试过了:
with tf.device("/cpu:0"):
我也想试试:
sess = tf.Session(config=tf.ConfigProto(intra_op_parallelism_threads=NUM_THREADS))
但我不明白如何使用“sess”来训练模型。
脚本每集运行大约需要 64 秒。我的问题:如何确保我的 python 脚本利用所有 CPU 内核,从而减少训练模型所需的时间。
制作模型的功能:
def OurModel(input_shape, action_space):
X_input = Input(input_shape)
# 'Dense' is the basic form of a neural network layer
# Input Layer of state size(4) and Hidden Layer with 512 nodes
X = Dense(512, input_shape=input_shape, activation="relu", kernel_initializer='he_uniform')(X_input)
# Hidden layer with 256 nodes
X = Dense(256, activation="relu", kernel_initializer='he_uniform')(X)
# Hidden layer with 64 nodes
X = Dense(64, activation="relu", kernel_initializer='he_uniform')(X)
# Output Layer with # of actions: 2 nodes (left, right)
X = Dense(action_space, activation="linear", kernel_initializer='he_uniform')(X)
model = Model(inputs = X_input, outputs = X, name='CartPole DQN model')
model.compile(loss="mse", optimizer=RMSprop(lr=0.00025, rho=0.95, epsilon=0.01), metrics=["accuracy"])
包含 model.fit 和 model.predict 的函数
def act(self, state):
if np.random.random() <= self.epsilon:
return random.randrange(self.action_size)
else:
return np.argmax(self.model.predict(state))
和
def replay(self):
if len(self.memory) < self.train_start:
return
# Randomly sample minibatch from the memory
minibatch = random.sample(self.memory, min(len(self.memory), self.batch_size))
state = np.zeros((self.batch_size, self.state_size))
next_state = np.zeros((self.batch_size, self.state_size))
action, reward, done = [], [], []
# do this before prediction
# for speedup, this could be done on the tensor level
# but easier to understand using a loop
for i in range(self.batch_size):
state[i] = minibatch[i][0]
action.append(minibatch[i][1])
reward.append(minibatch[i][2])
next_state[i] = minibatch[i][3]
done.append(minibatch[i][4])
# do batch prediction to save speed
target = self.model.predict(state)
target_next = self.model.predict(next_state)
for i in range(self.batch_size):
# correction on the Q value for the action used
if done[i]:
target[i][action[i]] = reward[i]
else:
# Standard - DQN
# DQN chooses the max Q value among next actions
# selection and evaluation of action is on the target Q Network
# Q_max = max_a' Q_target(s', a')
target[i][action[i]] = reward[i] + self.gamma * (np.amax(target_next[i]))
# Train the Neural Network with batches
self.model.fit(state, target, batch_size=self.batch_size, verbose=0)
让我知道是否需要更多代码。请回答我。谢谢你。