OpenBLAS Warning: Detect OpenMP Loop and this application may hang. Please rebuild the library with USE_OPENMP = 1 option

Hello,

I am using yolov5 from YoloV5 but when I run that on my Nvidia Jetson Nano B01 I get the following message.

OpenBLAS Warning: Detect OpenMP Loop and this application may hang. Please rebuild the library with USE_OPENMP = 1 option.

I think that has something to do with OpenCV, why the Jetson Nano is so slow even then.

Does anyone have any idea why this is and how I can fix it?

Thank you

Hi,

The error indicates the OpenBLAS doesn’t build with OpenMP support.
But YOLOv5 source do use OpenMP for acceleration.

To workaround this, you can try to set OMP_NUM_THREADS=1 to turn-off multi-thread.
Or you can re-install OpenBLAS from source by compiling it with USE_OPENMP=1.

Thanks.

Hi,

OK. Can you tell me how to reinstall OpenBlas from the source and compile with USE_OPENMP = 1

Thanks

Hi,

Please check the below for the details:

Thanks.