[FIRM] Invitation to Parallel Computing Colloquium

[Sabri Pllana]

Department of Scientific Computing of the University of Vienna Invites
to the Parallel Computing Colloquium

On WEDNESDAY, 2. June, 2010, 10:00 (s.t.), Hörsaal 1, UZA II
- Areal Althanstraße
   http://www.wegweiser.ac.at/ww5/static/plaene/pdf/A_UP-uza.pdf
- UZA II
   http://www.wegweiser.ac.at/static/plaene/pdf/A_UZA-II.pdf

Speaker:
Prof. Uzi Vishkin
University of Maryland
USA

Title:
Using Simple Abstraction to Guide the Reinvention of Computing for 
Parallelism

Abstract:
The sudden shift from single-processor computer systems to 
many-processor parallel ones requires reinventing much of Computer 
Science (CS): how to actually build and program the new parallel 
systems. CS urgently requires convergence to a robust parallel 
general-purpose platform that provides good performance and is easy 
enough to program by at least all CS majors. Unfortunately, lesser 
ease-of- programming objectives have eluded decades of parallel 
computing research. The idea of starting with an established easy 
parallel programming model and build an architecture for it has been 
treated as radical by vendors. This talk advocates a more radical idea. 
Start with a minimalist stepping-stone: a simple abstraction that 
encapsulates the desired interface between programmers and system 
builders. An Immediate Concurrent Execution (ICE) abstraction proposal 
is followed by two specic contributions: (i) A general-purpose many-core 
Explicit Multi-Threaded (XMT) computer architecture. XMT was designed 
from the ground up to capitalize on the huge on-chip resources becoming 
available in order to support the formidable body of knowledge, known as 
PRAM (for parallel random-access machine, or model) algorithmics, and 
the latent, though not widespread, familiarity with it. (ii) A 
programmer?s workow that links: ICE, PRAM algorithmics and XMT 
programming. The synchronous PRAM provides ease of algorithm design, and 
ease of reasoning about correctness and complexity. Multi-threaded 
programming relaxes this synchrony for implementation. Directly 
reasoning about soundness and performance of multi-threaded code is 
generally known to be error prone. To circumvent that, the work 
incorporates multiple levels of abstraction: the programmer must only 
establish that the multi-threaded program behavior matches the PRAM-like 
algorithm it implements, a much simpler task. Current XMT hardware and 
software prototypes, and demonstrated ease-of-programming and strong 
speedups suggest that we may be much better prepared for the challenges 
ahead than many realize. In fact, by the Goldstine, von-Neumann 1947 
formative paper on the serial paradigm our approach is not radical at 
all. Tenets such as not compromising the ease and speed of the human 
process and the harnessing of mathematical induction may be as old as 
computing itself. However, to meet the then extreme scarcity of 
hardware, the 1947 paper constrained induction with what the prevailing 
CS doctrine has come to consider "natural" and/or "simple". Helped by 
XMT hardware patents, ICE augments induction with a rudimentary 
abstraction that sidesteps this von-Neumann mental and hardware bottleneck.

Bio:
Prof. Uzi Vishkin started his work on parallel computing in 1979 as a 
PhD student at the Technion, Israel. His initial focus was on parallel 
algorithms and parallel algorithmic thinking. The 1982 Shiloach-Vishkin 
work-depth methodology for presenting parallel algorithms provided the 
presentation framework in several parallel algorithm (known as PRAM 
algorithms) texts that also include a considerable number of parallel 
algorithms he co-authored. In 1996, he was elected ACM Fellow for, among 
other things, having "played a leading role in forming and shaping what 
thinking in parallel has come to mean in the fundamental theory of 
Computer Science". He is also an ISI-Thompson Highly Cited Researcher. 
This parallel algorithms theory provided the basis for Prof. Vishkin's 
invention of the PRAM-On-Chip desktop supercomputer framework that 
scales beyond 1000 processors on chip. He later led its extensive 
hardware and software prototyping, including a 64-processor computer 
that has already been programmed by over 100 middle-school and 
high-school students. He was named a Maryland Innovator of the Year for 
his PRAM-On-Chip venture, whose main patent has been widely cited in 
patents of the major vendors. A follow-up proposal, entitled Center for 
Reinvention of Computing for Parallelism, ranked first among 49 
proposals in a recent University System of Maryland (USM) wide 
competition for Maryland Research Centers of Excellence. He has been 
Professor of Electrical and Computer Engineering at the University of 
Maryland Institute for Advanced Computer Studies (UMIACS) since 1988. He 
was affiliated with Tel Aviv University between and 1984 and 1997, and 
was Chair of CS there in 1987-8, and also worked for IBM T.J. Watson and 
New York University.