ExtOS: Data-centric Extensible OS

Today's computer architectures are fundamentally different than a decade ago: IO devices and interfaces can sustain much higher data rates than the compute capacity of a single threaded CPU. To meet the computational requirements of modern applications, the operating system (OS) requires lean and optimized software running on CPUs for applications to fully exploit the IO resources. Despite the changes in hardware, today's traditional system software unfortunately uses the same assumptions of a decade ago---the IO is slow, and the CPU is fast. This paper makes a case for the data-centric extensible OS, which enables full exploitation of emerging high-performance IO hardware. Based on the idea of minimizing data movements in software, a top-to-bottom lean and optimized architecture is proposed, which allows applications to customize the OS kernel's IO subsystems with application-provided code. This enables sharing and high-performance IO among applications---initial microbenchmarks on a Linux prototype where we used eBPF to specialize the Linux kernel show performance improvements of up to 1.8× for database primitives and 4.8× for UNIX utility tools.