Sirocco: Cost-Effective Fine-Grain Distributed Shared Memory
Software Fine-Grain Distributed Shared Memory (FGDSM) provides a simplified shared-memory programming interface with minimal or no hardware support. Originally software FGDSMs targeted uniprocessor-node parallel machines. This paper presents Sirocco, a family of software FGDSMs implemented on a network of low-cost SMPs. Sirocco takes full advantage of SMP nodes by implementing inter-node sharing directly in hardware and overlapping computation with protocol execution. To maintain correct shared-memory semantics, however, SMP nodes require mechanisms to guarantee atomic coherence operations. Multiple SMP processors may also result in contention for shared resources and reduce performance.