David I. August
Professor in the Department of Computer Science, Princeton University
Visiting Professor in the Department of Electrical Engineering, Columbia University
Affiliated with the Department of Electrical Engineering, Princeton University
Ph.D. May 2000, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign

Office: Computer Science Building Room 209
Email: august@princeton.edu
Phone: (609) 258-2085
Fax: (609) 964-1699

Front Page Publication List (with stats) Curriculum Vitae (PDF) The Liberty Research Group


Please beware of the "Princeton University - Part-Time Research Job" scam. I am not hiring remote research assistants for the Department of Computer Science. Anyone doing so would use a campus address or phone number. Princeton students, please visit the Phish Bowl before responding to unsolicited communication.


Hardware MultiThreaded Transactions [abstract] (ACM DL, PDF)
Jordan Fix, Nayana P. Nagendra, Sotiris Apostolakis, Hansen Zhang, Sophie Qiu, and David I. August
Proceedings of the Twenty-Third International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS), March 2018.
Accept Rate: 17% (56/319).

Speculation with transactional memory systems helps programmers and compilers produce profitable thread-level parallel programs. Prior work shows that supporting transactions that can span multiple threads, rather than requiring transactions be contained within a single thread, enables new types of speculative parallelization techniques for both programmers and parallelizing compilers. Unfortunately, software support for multi-threaded transactions (MTXs) comes with significant additional inter-thread communication overhead for speculation validation. This overhead can make otherwise good parallelization unprofitable for programs with sizeable read and write sets. Some programs using these prior software MTXs overcame this problem through significant efforts by expert programmers to minimize these sets and optimize communication, capabilities which compiler technology has been unable to equivalently achieve. Instead, this paper makes speculative parallelization less laborious and more feasible through low-overhead speculation validation, presenting the first complete design, implementation, and evaluation of hardware MTXs. Even with maximal speculation validation of every load and store inside transactions of tens to hundreds of millions of instructions, profitable parallelization of complex programs can be achieved. Across 8 benchmarks, this system achieves a geomean speedup of 99% over sequential execution on a multicore machine with 4 cores.