Get RuntimeError: One of the differentiated Tensors does not require grad in pytorch lightning

This is the key part in configure_optimizers() function in pytorch lightning:

params = []
train_names = []
print("Training only unet attention layers")
for name, module in self.model.diffusion_model.named_modules():
    if isinstance(module, CrossAttention) and name.endswith('attn2'):
        # Set requires_grad=False for all other parameters
        for param in module.parameters():
            param.requires_grad = False
opt = torch.optim.AdamW(params, lr=lr)

Guessing without a repro but can you try explicitly setting param.requires_grad = True in your if condition

Hi Marksaroufim,

Thank you for replying.

What I want to do here is only setting attention parameters requires_grad = True and passing them to the optimizer.
It did work if I set all the parameters with requires_grad = True.

I just found out that this error seems to be caused by the custom-defined class CheckpointFunction(torch.autograd.Function)
and I just made the code work by simply avoiding using this class