如何检查 TPU 在 Google Colab 中是否可用？

Question

我正在尝试根据 TPU 的可用性选择分配策略。

我的代码如下：

import tensorflow as tf
if tf.config.list_physical_devices('tpu'):
  resolver = tf.distribute.cluster_resolver.TPUClusterResolver()
  tf.config.experimental_connect_to_cluster(resolver)
  tf.tpu.experimental.initialize_tpu_system(resolver)
  print("All devices: ", tf.config.list_logical_devices('TPU'))
  strategy = tf.distribute.experimental.TPUStrategy(resolver)
else:  # use default strategy
  strategy = tf.distribute.get_strategy() 

但是不行。

如何识别 TPU？

Answer 1

以下代码有效：

import tensorflow as tf
try:
  resolver = tf.distribute.cluster_resolver.TPUClusterResolver()
  tf.config.experimental_connect_to_cluster(resolver)
  tf.tpu.experimental.initialize_tpu_system(resolver)
  print("All devices: ", tf.config.list_logical_devices('TPU'))
  strategy = tf.distribute.experimental.TPUStrategy(resolver)
except ValueError:
  strategy = tf.distribute.get_strategy()