George Prekas

I work as a Software Engineer at The D. E. Shaw Group. I have previously worked at Enfabrica and Amazon Web Services.

I received my PhD in 2018 from EPFL in Switzerland where I was advised by Prof. Edouard Bugnion and funded by a Google PhD Fellowship since 2015. My thesis is titled "Bridging the gap between dataplane OS and commodity OS". During my PhD, I did an internship at Microsoft Research in Redmond, WA in 2015 and at VMware in Palo Alto, CA in 2016. I received my M.Sc. in Electrical and Computer Engineering from the National Technical University of Athens in 2010.

Email / Google Scholar / LinkedIn / GitHub / Blog

Interests

I am interested in virtualization, operating systems, and networking. My academic contributions include:

• Improving datacenter performance, application latency, and energy efficiency.
• Optimizing the behavior of microsecond-scale tasks through enhancements of the underlying operating system and virtualization infrastructure.

In general, I enjoy building and understanding complex computer systems.

Projects

ZygOS

I have designed and implemented a new dataplane operating system named ZygOS, which features a work-conserving scheduler for microsecond-scale networked tasks.

ZygOS is a system optimized for microsecond-scale, in-memory computing on multicore servers. It implements a work-conserving scheduler within a specialized operating system designed for high request rates and a large number of network connections. ZygOS uses a combination of shared-memory data structures, multi-queue NICs, and inter-processor interrupts to rebalance work across cores.

IX

I have designed and implemented the energy management subsystem of the dataplane operating system IX.

IX is a dataplane operating system that provides high I/O performance and high resource efficiency while maintaining the protection and isolation benefits of existing kernels. IX uses hardware virtualization to separate management and scheduling functions of the kernel (control plane) from network processing (dataplane).

Dune

While working on IX and ZygOS, I have contributed multiple features to the kernel module Dune, which is a special purpose virtualization hypervisor.

Awards

• Google European Doctoral Fellowship in Operating Systems (2015)
• OSDI '14 Jay Lepreau Best Paper Award

Fun stuff

• Screencast of using Process Monitor, IDA Pro, and SoftICE to find a bug in Windows XP triggered by the Adobe Flash player. The bug was prohibiting the monitor from turning off for power saving. You can read the write up in my blog: Windows XP: My monitor does not turn off for power saving and watch the screencast on YouTube: Part 1, Part 2.

Publications

• [ATC] R2P2: Making RPCs first-class datacenter citizens
  Marios Kogias, George Prekas, Adrien Ghosn, Jonas Fietz, and Edouard Bugnion
  In Proceedings of the 2019 USENIX Annual Technical Conference. USENIX ATC, 2019
• [SOSP] ZygOS: Achieving low tail latency for microsecond-scale networked tasks
  George Prekas, Marios Kogias, and Edouard Bugnion
  In Proceedings of the 26th ACM Symposium on Operating Systems Principles. SOSP, 2017
• [TOCS] The IX operating system: Combining low latency, high throughput, and efficiency in a protected dataplane
  Adam Belay, George Prekas, Mia Primorac, Ana Klimovic, Samuel Grossman, Christos Kozyrakis, and Edouard Bugnion
  ACM Transactions on Computer Systems (TOCS), 34(4):11, 2016
• [OSDI] History-based harvesting of spare cycles and storage in large-scale datacenters
  Yunqi Zhang, George Prekas, Giovanni Matteo Fumarola, Marcus Fontoura, Inigo Goiri, and Ricardo Bianchini
  In Proceedings of the 12th USENIX conference on Operating Systems Design and Implementation. OSDI, 2016
• [SOCC] Energy proportionality and workload consolidation for latency-critical applications
  George Prekas, Mia Primorac, Adam Belay, Christos Kozyrakis, and Edouard Bugnion.
  In Proceedings of the Sixth ACM Symposium on Cloud Computing, pages 342–355. SOCC, 2015
• [OSDI] IX: A protected dataplane operating system for high throughput and low latency
  Adam Belay, George Prekas, Ana Klimovic, Samuel Grossman, Christos Kozyrakis, and Edouard Bugnion
  In Proceedings of the 11th USENIX Symposium on Operating System Design and Implementation (OSDI). OSDI, 2014
• XML Constructs for Developing Dynamics Applications or Towards a Universal Representation of Particle Accelerators in XML
  J Chrin, L Hubert, R Krempaska, G Prekas, and T Pelaia
  Proceedings of IPAC2011, San Sebastián, Spain
• A Taste of CAFE
  J Chrin and G Prekas
  Proceedings of ICALEPCS2009, Kobe, Japan
• miRGen 2.0: a database of microRNA genomic information and regulation
  Panagiotis Alexiou, Thanasis Vergoulis, Martin Gleditzsch, George Prekas, Theodore Dalamagas, Molly Megraw, Ivo Grosse, Timos Sellis, and Artemis G Hatzigeorgiou
  Nucleic acids research, 38(suppl 1):D137–D141, 2009
• Performance of laboratory experiments over the internet: Towards an intelligent tutoring system on automatic control
  Kleanthis Prekas, Maria Rangoussi, Savvas Vassiliadis, and George Prekas
  Int. J. Inf. Commun. Eng, 1(4):208–211, 2005

Patents

• Harvesting spare storage in a data center
  Ricardo Bianchini, Inigo Goiri Presa, Marcus Felipe Fontoura, Georgios Prekas
  US Patent 20,170,374,144, 2016