External validation

The research being undertaken in the CSA group is long-term and fundamental. It has the potential to revolutionise the way in which microprocessors and embedded systems are designed and, more importantly, implemented. Our research goals are rooted in the exponential growth curves of silicon systems and are solving problems due to this scaling that are beginning to become apparent on a small scale even today. Our work on Dynamic RISC (DRISC) processors for example has the potential to provide scalable chip multi-processors with hundreds of thousands of multi-processors, where the industry is currently struggling with the programming problems of a few on-chip processors. This work would allow binary code compatibility from today’s small-scale concurrency to the end of silicon scaling. Because of the long-term nature of the research, it is difficult to directly evaluate the social impact of this very technical work, however the techno-logical relevance can be measured by the impact our research has for companies like Philips, NXP, ACE, Recore Systems and Chess, with whom we closely collaborate. These companies provide tools or compo-nents for embedded systems and we note that our work has the potential to make such computing systems more ubiquitous, more energy efficient, more cost-effective, and more easily designed. More recently, we have also had interest from mainstream processor vendors, such as Intel and Sun Microsystems.

Through our large network of industry contacts the results of our research will find their way to industry.

Conversely, the industry provides us with relevant case studies. The CSA group has a good track record in valorization. For example, CSA’s Sesame system-level modeling and simulation framework is broadly used by both academic and industrial groups from all over the world. Moreover, together with the group of Prof.

Deprettere at Leiden University, the CSA group received a Valorization grant in 2008 from STW/Progress+

to further improve the deployability of our system-level design methodology research.

B.7 Researchers and other personnel

The CSA group is growing steadily, although it still is relatively small. Currently, the permanent CSA staff comprise one full professor, one associate professor and, since September 2008, one half-time assistant professor. The latter (half-time) position is a replacement for our previous, full-time assistant professor Dr.

Peter Knijnenburg, who unfortunately died in 2007 following a long period of illness. It turned out to be very difficult to find a good replacement for Dr Knijnenburg’s position, as compiler experts are scarce and sought after. Fortunately, we were able to attract Dr. Clemens Grelck for this position, who started work in the CSA group in September 2008 and has some ten years experience in compiler design. The position is part-time as it is combined with a readership at the University of Hertfordshire, UK, one of our key collaborators. In addition, we have one programmer (funded by a combination of direct and contract funding), and nine PhD students and two researchers funded from project related funds.

Training and education of CSA PhD students is organized in the context of the Dutch graduate school ASCI.

Besides participation in ASCI courses, our PhD students are also stimulated to participate in high-quality international summer schools, such as the International Summer School on Advanced Computer Architecture and Compilation for Embedded Systems, which is organized by the HiPEAC Network of Excellence (NoE) on an annual basis. Moreover, personal development through short-term student exchanges is also stimu-lated. For this purpose, we typically use exchange grants from the HiPEAC NoE. So far, we have received HiPEAC grants for student exchanges between our group and NXP, Koc University in Istanbul, University

of Erlangen-Nuremberg and UPC Barcelona.

A detailed overview of CSA’s research staff in the period 2004-2008 is provided in Table 2.1.

Table 2.1 Research staff of Computer Systems Architecture.

Program CSA 2002 2003 2004 2005 2006 2007 2008

fte fte fte fte fte fte fte

Full

professors C.R. Jesshope 0.2 0.4 0.4 0.4 0.4 Associate

professors A.D. Pimentel 0.2

A.D. Pimentel 0.2 0.4 0.4 0.4 0.2

C. Grelck 0.1

Assistant professors

P. Knijnenburg 0.1 0.4

Tenured staff

Supporting

Staff S. Polstra

Total tenured staff 0.4 0.9 1.2 0.8 0.9

T. Pronk 0.4 0.3 0.2

C. Erbas 0.2

Non tenured staff

M. Hicks 0.2

Total non tenured staff 0.4 0.3 0.4 0.2

C. Erbas 0.4 0.7 0.7

K. Bousias 0.3 0.7 0.7 0.7 0.7

M. Thompson 0.6 0.7 0.7 0.7

T. Bernard 0.7 0.7 0.7

L. Zhang 0.7 0.7 0.7

L. Guang 0.6 0.7 0.2

PhD candidates

M. van Tol 0.5 0.5

M. Lankamp 0.4 0.7

T. Taghavi 0.2 0.7

R. Poss 0.2

J. Masters 0.3

Total PhD candidates 0.7 2.0 4.1 4.6 5.4

TOTAL RESEARCH STAFF 1.1 3.3 5.6 5.8 6.5

B.8 Resources, funding and facilities

The CSA group uses a wide range of (computer) equipment, ranging from standard office computers and laptops to high-performance multi-core servers and FPGA prototyping boards. Recently, the group acquired a 16-node compute server, which is used for benchmarking of parallel programs, architectural simulations, design space exploration experiments and so on. Also, we have recently acquired a number of Xilinx Virtex-4 FPGA boards for prototyping our system designs.

In terms of funding in the period 2004–2008, our group has received 3 grants from NWO (one NWO Glance grant, two NWO Free Competition grants), two STW grants (one Progress grant, one Progress+ Valorisation grant), and three EU grants (one FP6 grant where CSA acts as sub-project leader, one FP7 grant of which CSA is coordinator, and one Artemis grant). Where we mostly relied on direct funding in the first few years of the group’s existence, we have now established a stable situation in which we obtain approximately 75%

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of our funds from research funds (NWO, STW) and contracts (EU). A detailed overview of our funding percentages is shown in Table 2. Because of our closeness to the computer industry, our-long term aim is to have a substantial proportion of funding coming from collaborative funds (both EU and STW) with funda-mental research (up to 25%) being undertaken under the remit of NWO funding.

Table 2.2 Funding of Computer Systems Architecture

Funding 2002 2003 2004 2005 2006 2007 2008 average

Direct funding fte’s 36% 27% 21% 14% 14% 19%

Research funds and contract fte’s 64% 73% 79% 86% 86% 81%

Total 100% 100% 100% 100% 100% 100%

(Unfortunately, the faculty’s backoffice does not support splitting the research funds and contract fte’s in separate categories in a consistent and reliable manner.)

B.9 Overview of the results

An overview of CSA’s productivity in terms of publications is shown in Table 2.3. A full outcome list for the CSA program is provided in Appendix B2.

KEY PUBLICATIONS

1. C.R. Jesshope, “Operating Systems in Silicon and the Dynamic Management of Resources in Many-core Chips”, in Parallel Processing Letters (PPL), pp. 257-274, Vol. 18 (No. 2), 2008

2. K. Bousias, L. Guang, C.R. Jesshope and M. Lankamp, “Implementation and evaluation of a mi-crothread architecture”, Journal of Systems Architecture, 2008, DOI 10.1016/j.sysarc.2008.07.001 3. K. Bousias, N.M. Hasasneh and C.R. Jesshope, “Instruction-level parallelism through

microthread-ing - a scalable Approach to chip multiprocessors”, Computer Journal, 49 (2), pp 211-233, 2006.

4. A.D. Pimentel, C. Erbas, and S. Polstra “A Systematic Approach to Exploring Embedded System Architectures at Multiple Abstraction Levels”, IEEE Transactions on Computers, pp. 99-112, Vol.

55 (No. 2), Feb. 2006.

5. C. Erbas, S. Cerav-Erbas and A. D. Pimentel, “Multiobjective Optimization and Evolutionary Algo-rithms for the Application Mapping Problem in Multiprocessor System-on-Chip Design”, in IEEE Transactions on Evolutionary Computation, pp. 358-374, Vol. 10 (No. 3), June 2006.

Table 2.3 Program results: outcome numbers of Computer Systems Architecture

2002 2003 2004 2005 2006 2007 2008 sum

2002-2008

a. in refereed journals 0 0 7 4 6 17

b. in refereed proceedings 3 4 8 11 10 36

1. Academic publications

c. book chapters 0 0 0 0 0 0

d. other academic publ. 0 0 0 0 0 0

Total 3 4 15 15 16 53

2. Monographs 1 1 4 2 3 11

3. Ph.D. theses 0 0 1 0 0 1

4. Professional publications and products 0 0 0 0 1 1 B.10 Analysis, perspectives and expectations for the research program

Strengths • The CSA group addresses highly important conceptual problems in com-puter architecture, such as massive concurrency and design complexity, and works on revolutionary rather than evolutionary solutions to these problems.

• In the few years of its existence, the CSA group has managed to establish a good and solid research reputation, with expertise in architecture, compilers

and a growing interest in operating systems. Coupled with an extensive net-work of academic and industrial contacts, we believe this profile is a manda-tory one to explore this new generation of computing systems based on mas-sive, explicit concurrency.

Weaknesses • CSA still is a small research group, where much software-engineering work is needed (e.g., compiler construction, cycle-accurate as well as high-level simulator construction, etc.) before any tangible research results can be ob-tained. Thus, CSA currently lacks the critical mass needed to swiftly pursue its research goals. The following weakness is also related to this problem.

• Although we have made a considerable improvement in recent years, our output in terms of publications can be improved even further. Especially, we need to increase the number of papers to the absolute top conferences and journals.

Opportunities • Collaborations with national and international research groups with adjoin-ing expertise can be further extended to increase the critical mass of re-searchers working on the research challenges addressed by CSA. Especially, in the scope of the HiPEAC NoE there are ample of opportunities for such collaborations.

• Our DRISC and Microgrid tool-chain, consisting of a compiler and multiple simulators, has just become fully operational and other institutions are tar-geting their compilers to this framework. Thus, it will become much easier to produce more substantial research results that demonstrate the thesis that multi-core can become mainstream. As a result of this, our output in terms of publications should also increase.

Threats • The disruptive nature of the pioneering approach taken to our work on DRISC microgrids creates a large technology transfer gap making it difficult to find a strong industrial partner willing to put sufficient time and effort into technology transfer. As this work matures a failure to find such a partner may compromise further funding.

• The personnel costs charged internally by the UvA for research funds and especially contract positions are so exorbitant that these positions always need to be matched with direct funding from the research groups themselves.

Since CSA is small and therefore only has very limited resources for match-ing, this is a major threat for the growing potential of our group.

Analysis • The CSA strategy of taking a revolutionary approach to problems in archi-tecture has been a risky one that appears to be paying off. Work on system-level design for embedded systems is now mature and has strong industrial collaboration, which should ensure technology transfer. However, new di-rections will need to be established to keep this work on the leading edge.

With respect to our DRISC microgrid work, the recent focus has been on engineering issues, in providing a complete tool chain to cycle-accurate software emulation of the architecture. This is now in place and the focus must now change to demonstrating our claims for this architecture, namely its broad applicability, while isolating the end-users from difficult concur-rency issues. The potential weaknesses are being insured against by develop-ing new research directions based on the same tool chain but targetdevelop-ing a vir-tual architecture that can be implemented in software at different levels of granularity on different target architectures. This both broadens and strengthens the work at the ISA level.

Adjusted goals • N/A – we believe our goals are relevant and far sighted and although some risk is involved, our track record to date justifies this approach

Adjusted strategy • N/A – again our sytrategy seems to be paying off as the work being under-taken matures.

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