IOBufferMemoryDescriptor

IOBufferMemory is a term used to describe a memory region allocated to hold data being transferred through input/output channels. It serves as a buffer between producers and consumers of data, smoothing speed mismatches and enabling efficient data movement between devices, peripherals, and software layers.

In many systems, IOBufferMemory can be allocated from pageable or pinned memory. For devices that perform direct memory access (DMA), buffers often need to be physically contiguous and/or non-pageable to remain stable during transfers. Allocation may use kernel APIs that guarantee pinning and alignment; in user space, buffers may be exposed via memory mapping or shared with devices through mechanisms like DMA-buf, IOCTLs, or file mappings. Data movement might employ ring buffers, scatter-gather lists, or DMA descriptors, and the buffer may be organized for zero-copy paths to minimize CPU copies.

Lifecycle and synchronization: buffers are allocated, filled by a producer, handed off to a consumer or device, and eventually freed. Access is synchronized to avoid data races; memory visibility and cache coherence are important for performance and correctness. Performance considerations include alignment, cache-line padding, pinning strategy, and avoiding unnecessary copies. Security considerations include clearing sensitive data after use and proper isolation between processes when memory is shared.

Respecting platform specifics is important, as names, APIs, and capabilities vary between operating systems, kernel subsystems, and user-space frameworks. IOBufferMemory is a generic concept used across networking stacks, storage I/O, and graphics pipelines to optimize data flow.