Designing a Custom Multi-Level FIFO Scheduler with BPF_MAP_TYPE_QUEUE for sched_ext
The Production Problem
When you’re running multi-tenant systems or mixed workloads, Linux’s CFS scheduler treats everything equally. Your latency-sensitive API servers get the same treatment as batch processing jobs. Netflix discovered this the hard way during traffic spikes—cache warming tasks would compete with customer-facing requests, spiking P99 lat…
