I am facing a very strange issue. I am working with cuda 9.0 version of PyTorch and yesterday it was working properly in my system ( ubuntu 14.04). Today when I tried to run my model, I noticed that it is using CPU. When I looked into it, I found that torch.cuda.is_available() is returning false even though the cuda driver is available. How is it possible? It was working properly till yesterday. How can it change syddenly?