Turning Linux into a High-Performance Library OS with Flux

Modern high-performance applications increasingly bypass the host kernel for I/O and scheduling and rely on library OSes for operating-system services. High-performance library OSes are often built from scratch, but supporting unmodified applications requires reimplementing mature Linux semantics. Running Linux itself as a library OS avoids this cost, yet existing Linux-based designs remain slow. Our analysis of LKL shows that the main bottlenecks lie in the surrounding user-space runtime rather than Linux subsystems.