Meta· Llama / infrastructure

Modernizing the Meta Ads Service With an Open-Source Kernel Scheduler

At Meta’s scale, a few milliseconds of latency degradation can have a significant negative impact on ads performance. When a Linux kernel upgrade risked regressing latency across Meta’s ad serving fleet, we turned to sched_ext — the upstream, BPF-based extensible scheduling framework — to build a scheduling policy customized to the Ads delivery workload. The result: a 28% reduction in ads retrieval stage tail(99th percentile) latency, 3.28 megawatts(MW) power saving, and a 1.1% increase in the number of ads ranked, proving that workload-specific scheduling optimization can directly drive business value. Why Ads Latency Matters Meta’s ads serving fleet handles more than 5 million requests per second on average at the serving platform entry point, which is over 400 billion per day across all monetized surfaces 1 . Every millisecond shaved off the p99 latency makes the ads more relevant for people on our platforms, and better matches mean stronger ROI for advertisers. This provides a real opportunity to reduce latency through workload-specific scheduling. …

Announced

13 Jul 2026 16:00 UTC