Type of Talk:  UTCS Colloquium/Architecture

&nbs

p;Speaker/Affiliation:  David Brooks/Harvard University

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;Date/Time:  Friday, January 30, 2009  11:00 a.m.

Loca

tion ACES 2.402

Host:  Steve Keckler

Talk Title: "T

he Alarms Project: A Hardware/Software Approach to Addressing Voltage Emerg

encies"

Talk Abstract:

Reliable and efficient power deliv

ery is critical to high-performance, power-constrained computing systems.

As designers seek to contain the power consumption of microprocessors throu

gh reductions in supply voltage and power-saving techniques such as 

clock-gating, these systems suffer increasingly large power supply fluctua

tions due to the finite impedance of the power supply network. These supply
fluctuations, referred to as voltage emergencies, must be managed to gua

rantee correctness.  Traditional  approaches to address this pr

oblem incur high-cost or compromise power/performance efficiency. Our resea

rch seeks ways to handle these alarm conditions through a combined hardware

/software approach, motivated by root cause analysis of voltage emergencie

s revealing that many of these events are heavily linked to both program co

ntrol flow and microarchitectural events (cache misses and  pipeline

flushes).  This talk will discuss three aspects of the project: (1) a
fail-safe mechanism that provides hardware guaranteed correctness; (2) a

voltage emergency predictor that leverages  control flow and microarc

hitectural event information to predict voltage emergencies up to 16 cycles
in advance; and (3) a proof-of- concept dynamic compiler implementation t

hat demonstrates that dynamic code transformations can be used to eliminate
voltage emergencies from the instruction stream with minimal impact on&nbs

p; performance.

Speaker Bio:
David Brooks joined Harvard U

niversity in September of 2002 and is an Associate Professor of Computer Sc

ience.  Dr. Brooks received his  B.S. (1997) degree from the Un

iversity of Southern California and  his M.A. (1999) and Ph.D (2001)

degrees from Princeton University, all in Electrical Engineering.  P

rior to joining Harvard University,  Dr. Brooks was a Research Staff
Member at the IBM T.J. Watson  Research Center.  Dr. Brooks re

ceived an IBM Faculty Partnership  Award in 2004, an NSF CAREER awar

d in 2005, and a DARPA Young  Faculty Award in 2007.  His rese

arch interests include architecture and runtime software approaches to addr

ess power, reliability, and  variability issues for embedded and hi

gh-performance computer systems.