volatile gpu-util=0% when training

[actor1996]

here are the settings in https://github.com/HRNet/HRNet-Facial-Landmark-Detection/blob/master/experiments/wflw/face_alignment_wflw_hrnet_w18.yaml

GPUS: (0,1,2,)
WORKERS: 33
PRINT_FREQ: 3
...

I didn't change other options

as showed in the picture above, the gpus 0,1,2 I used for train hrnet got 0% usage

How could that happen, is it because too much time is spent on processing data with the cpu

[tianmaxingkong12]

Preprocessing takes too much time. It's just a snap by using nvidia-smi. when using watch , it 's not always zero.