There seem to be multiple issues in this topic, so I’ll try to address them separately:

If your code was running fine and suddenly runs out of memory without any software or code changes, you should check, if the GPU is empty or if another process is using memory via nvidia-smi.
Are you using the memory_format=torch.channels_last somewhere in your code and if so, could you post this code snippet so that we can have a look at the warning?
If you haven’t allocated any tensors on the GPU, torch.cuda.memory_summary() is expected to output empty allocations.