Communication Architectures for Parallel-Programming Systems

Bal, H.E. [Promotor]Tanenbaum, A.S. [Promotor

Designing Efficient Network Interfaces For System Area Networks

The network is the key component of a Cluster of Workstations/PCs. Its performance, measured in terms of bandwidth and latency, has a great impact on the overall system performance. It quickly became clear that traditional WAN/LAN technology is not too well suited for interconnecting powerful nodes into a cluster. Their poor performance too often slows down communication-intensive applications. This observation led to the birth of a new class of networks called System Area Networks (SAN). The ATOLL network introduces a new optimized architecture for SANs. On a single chip, not one but four network interfaces (NI) have been implemented, together with an on-chip 4x4 full-duplex switch and four link interfaces. This unique "Network on a Chip" architecture is best suited for interconnecting SMP nodes, where multiple CPUs are given an exclusive NI and do not have to share a single interface. It also removes the need for any additional switching hardware, since the four byte-wide full-duplex links can be connected by cables with neighbor nodes in an arbitrary network topology

KNEM: a Generic and Scalable Kernel-Assisted Intra-node MPI Communication Framework

International audienceThe multiplication of cores in today's architectures raises the importance of intra-node communication in modern clusters and their impact on the overall parallel application performance. Although several proposals focused on this issue in the past, there is still a need for a portable and hardware-independent solution that addresses the requirements of both point-to-point and collective MPI operations inside shared-memory computing nodes. This paper presents the KNEM module for the Linux kernel that provides MPI implementations with a flexible and scalable interface for performing kernel-assisted single-copy data transfers between local processes. It enables high-performance communication within most existing MPI implementations and brings significant application performance improvements thanks to more efficient point-to-point and collective operations