GPU OOM errors when appending result to list

Hello all I was wondering if someone could explain to me why this snippet of code causes my GPU to run out of memory:

outputs = []
slices = torch.rand(100, 3, 512, 512)
for batch_idx in range(0, 100, batch_size):
    slice_ = slices[batch_idx: batch_idx + batch_size].cuda()
    u_net_output = unet(slice_) 

Since I’ve moved the output of unet to the cpu, doesn’t that mean that it does not reside on the GPU anymore? Why is it causing OOM errors?

Don’t worry I figure it out, it was because the buffers aren’t flushed as I’m not doing the update step