Improving the
Simulation and Programmability of Future Multiprocessor Systems
Tuesday January 30, 2007
Hamerschlag Hall D-210
4:30 pm
Thomas
Wenisch
Carnegie Mellon University
The demand for computer system performance continues to grow to enable solutions to
previously infeasible computing problems. In the past, microarchitectural innovations
and processor frequency scaling have yielded exponential system performance
improvement. However, challenges in microprocessor design complexity, verification,
scalability, and power dissipation have driven the semiconductor industry to bet on
multi-core/multiprocessor systems as the primary avenue for continued performance
scaling.
Unfortunately, the multiprocessor paradigm creates many new challenges for the system
designer. In this talk, I present research done at Carnegie Mellon University to
address two such challenges: rapid system performance evaluation and improving
multiprocessor system programmability. Because hardware availability lags behind
system design efforts, designers frequently must resort to software simulation to
evaluate future system performance. Unfortunately, detailed simulation of a
uniprocessor system is already four orders of magnitude slower than actual hardware,
and simulation time grows at least linearly with the number of processors. In the
first portion of my talk, I present a rigorous statistical sampling methodology that
makes simulation-based studies of commercial software applications and realistic
system sizes tractable while providing quantified measures of statistical confidence
with each estimated performance metric. Maximizing the performance of multiprocessor
shared-memory applications is challenging because programmers must often write code
that obeys arcane and unintuitive rules of relaxed memory consistency models. In the
second portion of my talk, I show that, contrary to conventional wisdom,
multiprocessors can provide the simpler programming model of a strongly-ordered
memory system while matching or exceeding the performance under more relaxed memory
consistency models.
Tom Wenisch is completing his Ph.D. in Electrical and Computer Engineering at
Carnegie Mellon University this spring, specializing in computer architecture under
Prof. Babak Falsafi. Tom's past research focuses on stream-based prefetching,
multiprocessor memory system design and computer system performance evaluation. His
future research interests center on extending the historic trend of exponential
computer system performance improvement into the multi-core era.
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