UMEM
UMEM is an acronym used in information technology with multiple meanings depending on context. In networking software, UMEM most commonly denotes a memory region used by user-space packet processing to exchange data with the kernel without extra copying. The Linux AF_XDP framework uses UMEM as a shared memory pool that holds the actual packet payloads. Applications allocate and map an UMEM region, decide frame size and number of frames, and then populate ring buffers for transmitting and receiving packets. The kernel and user-space threads access the same UMEM region, enabling zero-copy packet paths and lower latency.
Within AF_XDP, the typical arrangement includes an UMEM buffer pool presented to user space as memory, plus
Other uses of the term UMEM appear in general software documentation as short for “user memory” or,
See also: XDP, AF_XDP, zero-copy, DMA, memory management, packet processing.