Create contiguous memory via NvBufSurfaceAllocate

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
1

Hello,

I am working with a Jetson AGX Orin board with L4T-35.5.0 and create NvBufSurface objects by NvBufSurfaceAllocate.
The filedescriptor of the created NvBufSurface object is given via VIDIOC_QBUF ioctl to a V4L2 driver.
This driver needs contiguous memory.
Sometimes this driver reject the created memory with
“contiguous chunk is too small 2031616/8294400”
My question is, how can I configure NvBufSurfaceAllocate to create contiguous memory.
I have tried to set the isContiguous parameter in the NvBufSurfaceAllocateParams input of NvBufSurfaceAllocate, but without success.

4

may I know what’s your actual steps to repo this failure?

5

Hi,
It is not guaranteed to have contiguous memory via NvBufSurfaceAllocate(). You may allocate CPU buffers and copy data into NvBufSurface.

6

If I have understand the strace log correctly, NvBufSurfaceAllocate uses the NVMAP_IOC_ALLOC ioctl call of the nvmap kernel driver to allocate memory.
This ioctl uses struct nvmap_alloc_handle as input parameter.
In case of nvmap_alloc_handle::flags with set NVMAP_HANDLE_PHYS_CONTIG bit the allocated memeory should be contiguous in ma opinion.
Also the iniput parameter structure of NvBufSurfaceAllocate contains a bool isContiguous member.

8

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.