USERPTR
USERPTR is a memory model supported by the Video4Linux2 (V4L2) API in Linux. In this model, the application allocates its own user-space buffers and provides pointers to the driver when queuing buffers for capture or output. The driver then uses those user-space buffers as the I/O targets, rather than allocating and managing buffers in kernel space or using DMA-BUF sharing.
How it works in practice varies by device and driver, but the common pattern is that the
Advantages of USERPTR include lower kernel memory usage for drivers and potentially simpler buffer management for
USERPTR is one of several V4L2 memory models, alongside MMAP and DMABUF. It remains useful in certain