Unable to use multiprocessing or GNU Parallel with VPI

Autonomous Machines Jetson & Embedded Systems Jetson AGX Orin
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1

Using the stereo disparity example provided for VPI 2.3.9, I would like to run this estimation for multiple images at the same time so as to saturate the GPUs and maximize throughput. When I use the example individually everything works as expected, but when the use the same code wrapped with multiprocessing I get VPI initialization errors. If I use GNU parallel to launch the example program, I can run it maximum two jobs, if I use greater than 2 jobs I get similar VPI initialization error.

While GNU Parallel the error is as follows

VPI_ERROR_INVALID_OPERATION: PVA is not available and may be oversubscribed in the system: PvaError_DeviceUnavailable
3

Hi,

Do you use the PVA backend?
The PVA has a limit (4) on the subscripted processes.

If not, please find the topic below for a workaround:

Thanks.

4

Hi,

I am using CUDA as the backend and not PVA. Also, the workaround you shared is for code using C++. I am using python. Could you suggest what should I change in this [code](VPI - Vision Programming Interface: Stereo Disparity [its the sample code for stereo that nvidia provides), that will help me enforce CUDA as backend flag while creating images?

5

Hi @AastaLLL , is there any updates you could share?

6

Hi @AastaLLL Could you please provide some update on this issue? I would really like to maximize the throughput on the jetson and this issue is blocking me from moving to production

7

Hi,

Sorry for the late update.

It should work if you create the image with the backend|VPI_BACKEND_CUDA flag.
Could you give it a try?

Thanks.