调用train_on_batch、fit等时，Keras使用了太多的GPU内存

I've been messing with Keras, and like it so far. There's one big issue I have been having, when working with fairly deep networks: When calling model.train_on_batch, or model.fit etc., Keras allocates significantly more GPU memory than what the model itself should need. This is not caused by trying to train on some really large images, it's the network model itself that seems to require a lot of GPU memory. I have created this toy example to show what I mean. Here's essentially what's going on:I've been messing with Keras, and like it so fa