A technical post explores optimizing spin-locks—locks that keep threads spinning on CPU rather than yielding—through incremental improvements in memory ordering and synchronization. By adjusting atomic memory orderings from sequential consistency to acquire-release semantics, the authors achieve 5.7x faster performance and 5.4x lower energy consumption compared to a naive implementation.
This article explores optimizing spin-locks in C++ through incremental improvements. Starting with a naive atomic-based implementation, the author demonstrates how adjusting memory ordering semantics and reducing cache coherency traffic can achieve 5.7x faster performance and 5.4x lower energy consumption.