dqBuffer block when encode data in the background

I run the 01_video_encode sample in the background,It often blocks in the dqBuffer function of dqThread without return anything for a long time.But when i run it in the foreground,this doesn’t happen. Now i’m confused,because there are no differences between the background and forground.The TX2 doesn’t run other code except the sample.

Anybody can suggests anything?

Thanks in advance.

Please try r28.3, it adds non-blocking mode. Please run 01_video_encode with ‘–blocking-mode 0’