增量训练报CPU相关错误

[kevin]

我在进行LAC模型增量训练的时候，报以下错误：

Error Message Summary:

PreconditionNotMetError: The number(4) of samples[words] of current batch is less than the count(10) of devices(CPU), currently, it is not allowed. You should set the environment variable CPU_NUM in the system to determine the number of devices you need. at (/paddle/paddle/fluid/framework/parallel_executor.cc:923)

刚开始训练还挺正常，没问题，后来训练数据越来越多，大概两百多条，训练出现该错误。
环境python3.6，ubuntu16