Recent Developments in Multi-Core Computing Systems

Abstract

The improvement of processor performance by increasing the clock rate has reached its technological limits. As a result, new processor generations rely on multiple processor cores on a chip in order to increase performance, while mitigating problems like energy consumption, heat dissipation and design complexity. We are now witnessing the emergence of multi-core processors in all markets from laptops and game consoles to servers and supercomputers. However, exploiting the full potential of multi-core computing systems for application programs is a highly complex task posing many open research questions.

The 2008 International Workshop on Multi-Core Computing Systems (MuCoCoS'08) was organized in Barcelona, Spain, March 7th. In total 20 papers were submitted to MuCoCoS'08, of which 10 papers were selected by the program committee for presentation. Each paper was thoroughly evaluated by members of the program committee based on the significance to the CFP, originality, and contribution to theory/practice. From the 10 papers presented at MuCoCoS'08 we have selected six papers for this special issue. The selected papers address a representative set of issues related to the recent developments in multi-core computing systems.

In the first paper - "An Asynchronous API for Numerical Linear Algebra" by A. R. Brodtkorb - an approach for general purpose computation on Graphics Processing Units (GPUs) using MATLAB is described. The applicability of the approach is demonstrated for several linear algebra algorithms.

The second paper - "On the Potential of NoC Virtualization for Multicore Chips" by J. Flich, S. Rodrigo, J. Duato, T. Sødring, A. G. Solheim, T. Skeie and O.Lysne - is a position paper that provides arguments in favor of Network-on-a-Chip (NoC) virtualization. It is argued that NoC virtualization, associated with topology agnostic routing, minimizes fragmentation, provides performance isolation, facilitates cache coherency, helps dealing with manufacturing defects, and makes it easy to turn off unused cores for energy saving. These arguments are supported by a series of simulation results.

In the third paper - "Single-pass List Partitioning" by L. Frias, J. Singler and P. Sanders - a new algorithm to partition a list into pieces is described, which is potentially useful for parallelizing problems on multi-core processors. The approach described in this paper requires a single pass over the list using sub-linear storage to perform the partitioning, while previous approaches require two passes. Authors evaluate their approach empirically using an AMD Opteron based system.

The fourth paper - "Efficient Implementation of WiMAX Physical Layer on Multi-core Architectures with Dynamically Reconfigurable Processors" by W. Han, Y. Yi, M. Muir, I. Nousias, T. Arslan and A. T. Edorgan - proposes the use of dynamically reconfigurable processors for wireless applications. A simulator for multi-core systems is used for the evaluation of the proposed approach.

In the fifth paper - "Latency Impact on Spin-lock Algorithms for Modern Shared Memory Multiprocessors" by J. C. Meyer and A. C. Elster - an empirical evaluation of spin-lock algorithms on IBM System p575+ and SGI Origin 3800 computing systems is presented.

The last paper - "Parallel Advanced Video Coding: Motion Estimation on Multi-cores" by S. Momcilovic and L. Sousa - presents a motion estimation technique for multimedia processing, and its parallelization on the Cell Broadband Engine processor. The authors report very good performance in terms of frame rate on the Cell processor. The paper presents details on work partitioning among the PPU and SPE's that may be applicable to other applications on Cell.

We are grateful to all authors for submitting their papers to MuCoCoS'08, to program committee members for their efforts to evaluate papers within a short period, and to David A. Bader for delivering the keynote speech. Furthermore, we would like to acknowledge the support of Marcin Paprzycki (SCPE editor-in-chief) and Alexander Denisjuk (SCPE technical and managing editor).

Special Issue Editors, Sabri Pllana and Siegfried Benkner.