Access Restriction

Author Thakur, R. ♦ Gropp, W. ♦ Lusk, E.
Source IEEE Xplore Digital Library
Content type Text
Publisher Institute of Electrical and Electronics Engineers, Inc. (IEEE)
File Format PDF
Copyright Year ©1999
Language English
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Identity-based encryption ♦ File systems ♦ Read only memory ♦ Mathematics ♦ Computer science ♦ Laboratories ♦ National electric code ♦ Control systems ♦ Parallel machines
Abstract The I/O access patterns of parallel programs often consist of accesses to a large number of small, noncontiguous pieces of data. If an application's I/O needs are met by making many small, distinct I/O requests, however, the I/O performance degrades drastically. To avoid this problem, MPI-IO allows users to access a noncontiguous data set with a single I/O function call. This feature provides MPI-IO implementations an opportunity to optimize data access. We describe how our MPI-IO implementation, ROMIO, delivers high performance in the presence of noncontiguous requests. We explain in detail the two key optimizations ROMIO performs: data sieving for noncontiguous requests from one process and collective I/O for noncontiguous requests from multiple processes. We describe how one can implement these optimizations portably on multiple machines and file systems, control their memory requirements, and also achieve high performance. We demonstrate the performance and portability with performance results for three applications-an astrophysics-application template (DIST3D) the NAS BTIO benchmark, and an unstructured code (UNSTRUC)-on five different parallel machines: HP Exemplar IBM SP, Intel Paragon, NEC SX-4, and SGI Origin2000.
Description Author affiliation: Div. of Math. & Comput. Sci., Argonne Nat. Lab., IL, USA (Thakur, R.)
ISBN 0769500870
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research ♦ Reading
Education Level UG and PG
Learning Resource Type Article
Publisher Date 1999-02-26
Publisher Place USA
Rights Holder Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Size (in Bytes) 87.83 kB
Page Count 8
Starting Page 182
Ending Page 189

Source: IEEE Xplore Digital Library