Linux Plumbers Conference 2025

How do we make a Steamdeck scheduler work on large servers

12 Dec 2025, 18:12

18m

"Hall B2 (63)" (Toranomon Hills Mori Tower)

sched_ext: The BPF extensible scheduler class MC sched_ext: The BPF extensible scheduler class MC

Speakers

David Dai (Meta) Ryan Newton (Meta)

Description

With the proliferations of many sched_ext schedulers, including ones that caters for very specific workloads within Meta. There exists a need for a "default" fleet scheduler that "just works" for a wide range of hardware and use cases. SCX_LAVD is one such candidate as one of the more mature sched_ext schedulers out there with various heuristics to favor latency critical threads.

The talk will focus on various challenges and strategies in bringing in SCX_LAVD and trying to run it on large production workloads and large topologies:

1. How do we handle large and varied topologies and cache hierarchies that exists in the fleet to take optimal advantage of the hardware?

2. How do we tune LAVD such that it performs well in throughput bound use cases without sacrificing its latency advantages?

3. How do we test and stress schedulers to prevent regressions from reaching production?