A Multi-thread Approach to Coalescing Small Transfers Generated by Portable Tool Sets

An approach to providing scientific users with the means to code complex algorithms in a natural way is to provide portable tool sets implementing the concepts of each scientific field. These tool sets facilitate implementation on massively parallel systems, but often tend toward large numbers of small inter-CPU data transfers, adversely impacting efficiency. We present techniques for mitigating this effect without affecting the way the user sees the tools. Efficiency improvements obtained by transfer coalescing via “multithreading” arc studied in the context of Lattice Gauge Theory computations. * Paper submitted for presentation at Supercomputing ‘93, as a TECHNICAL. PAPER. t M. Fischler (presenting author): mf@fnal.fnal.gov (708)&W4339 FAX (708)840-8208 tt M. Uchima: uchim@fnal.fnal.gov (708)840-2671 FAX (708)&M-8208 ** Fermilab is operated by Universities Research Association, Inc. under contract with the U.S. Deparmenl of Energy