https://stackoverflow.com/questions/34199233/how-to-prevent-tensorflow-from-allocating-the-totality-of-a-gpu-memory
https://github.com/BIGBALLON/cifar-10-cnn/blob/master/for_girl/00_original.py
https://github.com/BIGBALLON/cifar-10-cnn/blob/master/for_girl/02_set_momory.py
https://zhuanlan.zhihu.com/p/35186462