Multi-CPU problems

Hi, every one,
I am using pytorch 1.0.0 and want to use multi-cpu to speed up the computation.
The problem is when I use get_num_threads, I always get 1, even after I set_num_threads(20).

I searched for this problem. It seems to be something to do with MLK.
I am not sure if I installed the MLK.
Here is my questions:

  1. I installed the pytorch from pip. Is this MLK library ship with pytorch when I install it from pip?
  2. If it is shipped with pytorch, how can I fix this multi-CPU problem?
  3. If it does not ship with pytorch, in order to use MKL, do I need to install pytorch from source?