Real-time system paper wins 2025 “test of time” award
The award honors paper with longstanding impact on the field of embedded software
A team of WashU faculty and alumni has received recognition for a pioneering paper that has been influential in the field of embedded software for more than a decade.
The paper, titled "RT-Xen: Towards Real-time Hypervisor Scheduling in Xen," received the 2025 Test of Time award from EMSOFT, the flagship conference on embedded software. The award recognizes papers that are at least 10 years old and have had a longstanding impact.
The paper was presented at the ACM International Conference on Embedded Software in October 2011. The authors were Sisu Xi, who earned a doctorate in computer science & engineering from the Engineering school in 2014 and now works as a principal software engineer for Hebbia; Justin Wilson, who earned a doctorate in computer science & engineering from the Engineering school in 2016 and now works as a principal software engineer at Object Computing Inc.; Chenyang Lu, the Fullgraf Professor in the McKelvey School of Engineering and director of the AI for Health Institute; and Christopher Gill, professor of computer science & engineering in McKelvey Engineering.
The paper introduced RT-Xen, the first system to bring real-time scheduling to the widely used Xen hypervisor, a leading open-source virtualization platform. The WashU team, working with collaborators at the University of Pennsylvania, went on to develop the real-time deferrable server (RTDS) scheduler, which was adopted into the official Xen distribution. The inclusion of RTDS in the Xen hypervisor stands as a milestone in transferring real-time scheduling theory into widely used real-world system software.
“RT-Xen is a powerful example of how innovative ideas can move from theory into open-source software that benefits developers and users worldwide,” Lu said. “Receiving this award more than a decade later is a testament to our commitment to real-world impact and, above all, to the extraordinary talent and dedication of our students, faculty and collaborators.”
The award was presented at Embedded Systems Week 2025, an event covering all aspects of hardware and software design for intelligent and connected computing systems, in Taipei, Taiwan, from Sept. 28-Oct. 3.
Lu previously won two test of time awards in 2022.
