The elephant and the mice: the role of non-strict fine-grain synchronization for modern many-core architectures

  • Authors:

  • Juergen Ributzka;Yuhei Hayashi;Joseph B. Manzano;Guang R. Gao

  • Affiliations:

  • University of Delaware, Newark, DE, USA;University of Delaware, Newark, DE, USA;University of Delaware, Newark, DE, USA;University of Delaware, Newark, DE, USA

  • Venue:
  • Proceedings of the international conference on Supercomputing
  • Year:
  • 2011

Quantified Score

Hi-index 0.00

Visualization

Abstract

The Cray XMT architecture has incited curiosity among computer architect and system software designers for its architecture support of fine-grain in-memory synchronization. Although such discussion go back thirty years, there is a lack of practical experimental platforms that can evaluate major technological trends, such as fine-grain in-memory synchronization. The need for these platforms becomes apparent when dealing with new massive many-core designs and applications. This paper studies the feasibility, usefulness and trade-offs of fine-grain in-memory synchronization support in a real-world large-scale many-core chip (IBM Cyclops-64). We extended the original Cyclops-64 architecture design at gate level to support the fine-grain in-memory synchronization feature. We performed an in-depth study of a well-known kernel code: the wavefront computation. Several versions of the kernel were used to test the effects of different synchronization constructs using our chip emulation framework. Furthermore, we tested selected OpenMP kernel loops against existing software-based synchronization approaches. In our wavefront benchmark study, the combination of fine-grain dataflow-like in-memory synchronization with non-strict scheduling methods yields a thirty percent improvement over the best optimized traditional synchronization method provided by the original Cyclops-64 design. For the OpenMP kernel loops, we achieved speeds of three to fourteen times the speed of software-based synchronization methods.