Supporting Shared Memory and Message Passing on Clusters of PCs with a SMiLE

   Wolfgang Karl, Markus Leberecht, Martin Schulz

     Lehr- und Forschungseinheit Informatik X
  Rechnertechnik und Rechnerorganisation (LRR-TUM)
          Institut für Informatik der 
        Technischen Universität München
     Arcisstr. 21, D-80290 München, Germany
        karlw@informatik.tu-muenchen.de

                      Abstract

With the rise of fast interconnection technologies and
new concepts to utilize them without operating system interaction (like
VIA \cite{VIA-spec}), compute clusters are becoming increasingly 
commonplace. Most of the interconnection networks focus
only on message passing as their prime programming model neglecting
the large code basis for shared memory. However, by utilizing the 
Scalable Coherent Interface (SCI) \cite{SCIStandard} with
its ability to transparently perform remote memory operations,
it is possible to support both efficient message passing and
transparent shared memory on one single platform. This introduces
a previously unknown flexibility into the cluster architecture.