MadSystems Seminar

Jovan Stojkovic (UIUC) will give an invited talk in this week's MadSystems Seminar.

Abstract: Serverless computing enables scalable, cost-efficient, and simple to program applications by allowing users to develop their workloads as compositions of lightweight functions, while the cloud provider manages the underlying infrastructure. However, serverless workloads differ significantly from traditional cloud applications—they are short-lived, have smaller data and instruction footprints, experience bursty request arrival patterns, involve high I/O activity, and undergo frequent context switches. These characteristics result in performance, energy, and resource inefficiencies when run on conventional server-class processors.

To address these challenges, I introduce μManycore (ISCA ’23), a processor architecture optimized for serverless environments. Unlike traditional processors, μManycore focuses on minimizing tail latency, the key performance metric in cloud environments. It achieves this goal by removing the main contention points in the system. First, instead of having a chip-wide cache coherence, μManycore organizes its cores into small cache-coherent villages. Then, it connects the villages via a leaf-spine network topology that provides low-latency, redundant paths between clusters of villages. Finally, μManycore is augmented with a hardware support for request scheduling and context switching.

Building on μManycore, I propose Mosaic (MICRO ’24), a core micro-architecture optimized for serverless workloads. Mosaic slices micro-architectural structures, such as caches and branch predictors, into small chunks and assigns tiles of such chunks to functions. The processor retains the state of functions in their tiles across context switches, thereby improving performance. Furthermore, currently inactive tiles are set to a low power mode, thereby reducing energy consumption. Together, μManycore and Mosaic deliver significant improvements in tail latency, throughput, and power efficiency for serverless environments.

Bio: Jovan Stojkovic is a final year PhD student at the University of Illinois at Urbana-Champaign advised by Professor Josep Torrellas. His research interests are in hardware and software abstractions for cloud platforms and emerging computing paradigms, such as microservices and serverless computing. His work appeared in major computer architecture conferences, such as ISCA, MICRO, ASPLOS, and HPCA. He was awarded multiple distinctions, such as Mavis Future Faculty Fellowship, Young Researcher at the Heidelberg Laureate Forum, Kenichi Miura Award for excellence in high performance computing, and IEEE Top Picks Honorable Mention. He is currently at the academic job market.