IPCOverhead

IPCOverhead refers to the cost in time and resources associated with inter-process communication (IPC) between processes or threads. It encompasses context switches, transitions between user and kernel mode, data marshalling and copying, protocol processing, and synchronization. Different IPC mechanisms incur distinct overhead profiles, including pipes, message queues, Unix domain sockets, network sockets, and shared memory.

Shared memory often offers low data-transfer overhead because it avoids copying data between user and kernel spaces, but it can incur significant synchronization and memory coherence costs. In contrast, pipes and sockets typically involve more kernel mediation and data copying, which increases latency and reduces throughput but can simplify synchronization and access control. The chosen IPC primitive thus shapes the overall performance characteristics of an application or system.

Metrics used to characterize IPCOverhead include latency per operation, throughput (messages per second), CPU utilization, and jitter. These metrics are influenced by data size, operation frequency, concurrent participants, and whether IPC happens within a single host or across a network. Hardware and software factors, such as processor speed, cache locality, NUMA topology, and kernel version, also affect overhead.

Optimization approaches aim to reduce IPCOverhead while preserving correctness. Strategies include batching messages, zero-copy transfers where feasible, using shared memory with careful synchronization, reducing context switches through asynchronous or event-driven designs, and selecting the most appropriate IPC mechanism for the workload. In some high-performance or real-time environments, kernel bypass or user-space IPC techniques may further decrease overhead.