What will happen if back propagation multiple times before optimizer.step()?
Coincidentally, I got RuntimeError like this:
RuntimeError: Trying to backward through the graph a second time, but the buffers have already been freed. Specify retain_graph=True when calling backward the first time.
Which means I can back propagation multiple times before optimizer.step(). But what will happen if I do that?
Under what circumstances should I use like this?