When Meta went looking for a better Linux CPU scheduler for its massive server fleet, it didn't start in the data center. Instead, it started with a handheld gaming PC. In a recent technical talk at the Linux Plumbers' Conference in Tokyo, Meta engineers detailed how they've been deploying SCX-LAVD, a low-latency Linux scheduler originally developed by Valve for the Steam Deck, across production servers running everything from messaging backends to caching services. The surprising conclusion: a scheduler designed to keep games responsive under load turns out to be an excellent fit for large-scale data center workloads, too.
At a high level, a CPU scheduler decides which programs get to run on what CPU cores, and when. Linux's default scheduler has to work everywhere — phones, laptops, desktops, servers — which makes it extremely conservative. Meta's challenge is different: it runs enormous machines with hundreds of CPU cores, wildly varied workloads, and most critically, strict latency targets. In that environment, "good enough everywhere" often isn't good enough. Rather than building a custom scheduler for every service, Meta wanted something closer to a fleet-wide default, a "one size fits most" scheduler that could adapt automatically without hand-tuned configuration. That's where SCX-LAVD came in.
