Use mps in NVDEC error.

I use ffmpeg compiled with cuda, support nvdec to decode h264 in gpu devices. MPS( can share context with different processes, and this can use less gpu storage when use multi-process to decode h264 stream. But when I use ffmpeg in this mode, error got like this.

Input #0, mpeg, from ‘/data/yt_traffic/media/nianjianbiao.mp4’:
Duration: 00:16:57.97, start: 7833.134000, bitrate: 4219 kb/s
Stream #0:0[0x1e0]: Video: h264 (High), yuv420p(progressive), 1920x1080, 25 fps, 25 tbr, 90k tbn, 50 tbc
File ‘1.yuv’ already exists. Overwrite ? [y/N] y
[AVHWDeviceContext @ 0x4444840] Could not initialize the CUDA driver API
Stream mapping:
Stream #0:0 -> #0:0 (h264 (h264_cuvid) -> rawvideo (native))
Error while opening decoder for input stream #0:0 : Unknown error occurred

And, when mps is shutdown, ffmpeg works fine. Anyone can help?