We Replaced MMAP with Io_uring in Our Rust Query Engine. It Got Slower
Developers of a Rust‑based query engine swapped its memory‑mapped file access for the newer io_uring interface, hoping to improve I/O efficiency. Benchmarks after the change showed the engine running noticeably slower than with the original MMAP approach. The team analyzed the regression, attributing it to overhead in the io_uring path and planning further optimization in the near term.