Thanks.
Are you running some custom CUDA extensions? No, I am using https://colab.research.google.com/ 75
did you build PyTorch from source? No, I am using its modules and functions.
which GPU are you using? I am using https://colab.research.google.com/ 75 and I do not know what is it.
I found what caused this problem:
In colab, I should set that I want to run my code on gpu in Runtime menu.
Thanks a lot