Kernel Assisted Collective Intra-node Communication Among Multicore and Manycore CPUs
Teng Ma, George Bosilca, Aurélien Bouteiller, Brice Goglin, Jeffrey M. Squyres, Jack J. Dongarra · 2010
Even with advances in materials science, fundamental limits in heat and power distribution are preventing higher CPU clock frequencies. Industry solutions for increasing computation speeds have concentrated on raising the number of computational cores available, leading to the wide-spread adoption of so-called “fat ” nodes. However, keeping all the computation cores busy doing useful work is a challenge because typical high performance computing (HPC) workloads require reading and writing a steady stream of data from memory – contention for memory bandwidth becomes a bottleneck. Many commodity platforms have therefore embraced nonuniform memory access (NUMA) architectures that split up and distribute memory to be close to the cores. High-performance Message Passing Interface (MPI) implementations must exploit these architectures to provide reliable