PhD Seminar • Systems and Networking — SKQ: Event Scheduling for Optimizing Tail Latency in a Traditional OS Kernel

Friday, June 4, 2021 2:00 pm - 2:00 pm EDT (GMT -04:00)

Please note: This PhD seminar will be given online.

Oscar Zhao, PhD candidate
David R. Cheriton School of Computer Science

Supervisor: Professor Ali Mashtizadeh

Modern hardware and server applications have evolved since operating system event facilities were developed nearly 20 years ago. This paper presents Schedulable Kqueue (SKQ), a new design to FreeBSD Kqueue that improves various applications’ tail latency and usable low-latency throughput. SKQ introduces a new scalable architecture that gives applications better control of event delivery and event scheduling. We support multiple scheduling policies that improve cache locality and alleviate workload imbalances.

In the RocksDB benchmark, SKQ reduces tail latency by up to 1022x and extends the usable throughput by 27.4x. SKQ also closes the gap between traditional OS kernel networking and a state-of-the-art kernel-bypass networking system by 83.7% for an imbalanced workload.


Bio: Siyao (Oscar) Zhao is a 3rd year PhD student working with Ali Mashtizadeh. His research area is operating systems and networking.


To join this PhD seminar on Zoom, please go to https://zoom.us/j/92268050403?pwd=bVZyS2Nmc2QwRGZOQzNSbzBCM3ROUT09.