Program suspended when transform torch script to relay

I’m transforming torch script to relay using code like this:

mod_ts, params_ts = relay.frontend.from_pytorch(j_model, shape_list)

at jupyter notebook, I got the result, but at cmd I find the program suspended, and some massages appear in monitor like this:

[21:02:06] /root/tvm/src/relay/transforms/type_infer.cc:818: tvm::relay::transform::InferType [21:02:06] /root/tvm/src/ir/transform.cc:467: Executing module pass : RemoveUnusedFunctions with opt level: 1 [21:02:06] /root/tvm/src/ir/transform.cc:467: Executing module pass : InferType with opt level: 0 [21:02:06] /root/tvm/src/relay/transforms/type_infer.cc:818: tvm::relay::transform::InferType [21:02:06] /root/tvm/src/ir/transform.cc:467: Executing module pass : RemoveUnusedFunctions with opt level: 1 [21:02:06] /root/tvm/src/ir/transform.cc:467: Executing module pass : RemoveUnusedFunctions with opt level: 1 [21:02:06] /root/tvm/src/ir/transform.cc:467: Executing module pass : ToBasicBlockNormalForm with opt level: 1

anybody can tell me what happened? Thank you

my environ:

os: Ubuntu 18.04.5 LTS
cpu: Intel(R) Xeon(R) Silver 4116 CPU @ 2.10GHz
llvm: 6.0
tvm: 0.8.dev0

j_model is a huggingface Transformers BertModel