Adve Presents Heterogeneous Systems Research at DARPA ERI Summit

Started in 2017, the Electronics Resurgence Initiative (ERI) is a five-year $1.5 billion investment in defense electronic systems by the Defense Advanced Research Project Agency (DARPA). Each year, researchers leading aspects of the 19 different programs funded by the initiative are invited to share their research at an annual summit. This summer, Sarita Adve, the Richard T. Cheng Professor of Computer Science, was among the invited presenters.

Adve represented the EPOCHS (Efficient Programmability of Cognitive Heterogeneous Systems) project, funded by the DSSOC (Domain-Specific Systems-on-Chip) program within the ERI. The project, which was announced last year, is a collaboration with two other Illinois CS faculty, Vikram Adve, the Donald B. Gillies Professor of Computer Science, and Assistant Professor Sasa Misailovic, as well as researchers at IBM, Columbia University, and Harvard University. The group tackled the challenge of achieving continuous performance gains from general computer hardware, a task that has become increasingly challenging as the trajectory of Moore's Law has slowed.

Designers are currently focused on designing more specialized computer architectures that consist of many accelerators, each speeding up a different portion of the computation. The EPOCHS project is developing the hardware and software technologies to build and program such systems efficiently, using cognitive connected vehicles as an example of a target application domain. The Illinois team is responsible for the compiler, which is central to the programmability and energy efficiency of the chip, and for the memory system architecture which is central to the integration of the different accelerators and the efficiency with which they communicate. Adve presented the team’s research on both of these fronts and her presentation was well received, especially the proposed addition of the Spandex coherence interface, which enables efficient integration of widely disparate computational units and accelerators that use a variety of coherence mechanisms.

“After all the positive feedback we received at the summit, I am even more excited about implementing Spandex as part of the prototype chip that our EPOCHS team is working to tape out – it will be exciting to see the ideas in action on a real system,” said Adve. “We are also excited that the talk opened up discussions about directions our work needs to take to influence IBM’s products – we look forward to a broader set of collaborations with IBM.”

Underlying their research is the observation that clean interfaces are critical to the efficiency and programmability of heterogeneous systems. For the memory system, Spandex provides such an interface for efficient integration of heterogeneous coherence mechanisms. Spandex’s frictionless integration provides higher performance, lower energy, and much less complex design than the current state of the art. Over the last year, the Illinois team adapted Spandex for the application domain targeted by EPOCHS and showed even higher efficiency. For the software stack, the team has proposed Heterogeneous Parallel Virtual Machine (HPVM), a compiler intermediate representation and infrastructure that builds on the successful LLVM compiler infrastructure from Vikram Adve’s group to enable efficient heterogeneous resource management and optimization.

The team’s work attracted a lot of interest at the summit that encouraged Adve and her team.

“There was interest from corners I did not anticipate, such as government labs dealing with problems with heterogeneous system integration for high performance computing,” she said. “The talk seems to have reinforced the need for more investment from government agencies put towards solving this problem. Multiple practitioners and researchers also expressed they want to use HPVM and we plan to make it publicly available soon to enable broader adoption.”

In addition to Adve, Naresh Shanbhag, the Jack S. Kilby Professor of Electrical and Computer Engineering also presented at the ERI Summit, covering the FRANC (Foundations for Novel Compute) program.  Read more about FRANC in the original CSL story.