7/23/2021 Aaron Seidlitz, Illinois CS
Illinois CS PhD graduate Dimitrios Skarlatos, now a professor at Carnegie Mellon, honed a research interest in performance, security and scalability – resulting in a dissertation honored at ISCA 2021.
Written by Aaron Seidlitz, Illinois CS
While he was an Illinois CS student, Dimitrios Skarlatos (PhD CS ’20) molded a research focus that bridged computer architecture and operating systems, with a specific interest in performance, security and scalability.
His efforts culminated with the dissertation, “Rethinking Computer Architecture And Operating System Abstractions for Good & Evil,” which, in June, earned recognition as the 2021 ACM SIGARCH – IEEE-CS TCCA Outstanding Dissertation Award winner.
The dissertation provides an overview of current security challenges and highlights several solutions. His technical expertise combined with a great understanding of the current state of the industry, which helped the dissertation capture this recognition at ISCA 2021.
“Computing systems are undergoing a radical shift, propelled by stern security requirements and an unprecedented growth in data and users. This change has proven to be abstraction breaking,” Skarlatos said. “Current hardware and operating system abstractions were built at a time when we had minimal security threats, scarce compute and memory resources, and limited numbers of users. These assumptions are not representative of today’s computing landscape.
“In this new era of computing, it is urgent that we rethink the synergy between the OS and hardware layers from scratch.”
Attacks such as Meltdown and Spectre highlighted the fact that these issues had not been properly identified and solved. In response, Skarlatos’s work focused on two central themes and presented several different solutions.
First, he identified Jaimais Vu as a defense against “microarchitectural replay attacks.” Additionally, the dissertation outlined Draco operating system and hardware mechanisms for "low-overhead protections of the system-call interface by caching validated system calls and arguments.”
Second, the dissertation proposes Elastic Cuckoo Page tables as a “radical rethink of virtual memory translation that enable high translation parallelism.”
The Outstanding Dissertation Award served as the perfect acknowledgement of the years-long effort Skarlatos placed into his research focus and learning with advisor, Illinois CS professor Josep Torrellas.
“Dimitrios’ thesis is one of the best I have ever seen; it is both broad and deep at the same time, with groundbreaking new ideas and a wealth of data,” Torrellas said. “I find the part that introduces Elastic Cuckoo Page Tables the most significant. This represents a trail-blazing, better alternative to the state-of-the-art virtual address translation schemes of processors. It may revolutionize current designs.”
Similarly, the pupil credited Torrellas as a great advisor. Skarlatos said that as a teacher Torrellas presents a unique combination of research freedom and expertise. This properly guides his students to the right inquiries.
Additionally, Skarlatos felt fellow Illinois CS faculty Christopher Fletcher and Tianyin Xu – both of whom served on his doctoral committee – helped him bridge “computer architecture with security and operating systems leading to a unique research perspective that cuts across multiple layers.”
These people he worked closely with helped him persevere even as the research process created its own challenges, as it does to anyone experiencing it.
“Research is exciting because it always moves through hills and valleys that push you forward,” Skarlatos said. “I am intrigued by the interactions of software and hardware, especially considering some design decisions implemented more than two decades ago are still present in today's systems. My PhD would not have been the same without the influence of many faculty and students here at UIUC, but also through experiences I gathered from internships in industry.”
Moving forward, Skarlatos will begin as an assistant professor of Computer Science with Carnegie Mellon University in Fall 2021.
Thinking back on his time with Skarlatos, Torrellas said he understands why his former pupil is ready for the next phase of his academic journey.
“Dimitrios was always in a good mood, taking rejections and bad news in stride. He would also give ideas to more junior students continuously. Working with him was a great joy,” Torrellas said.