Parallel processing a real code: A case history
A three-dimensional, time-dependent Free-Lagrange hydrodynamics code has been multitasked and autotasked on a Cray X-MP/416. The multitasking was done by using the Los Alamos Multitasking Control Library, which is a superset of the Cray multitasking library. Autotasking is done by using constructs which are only comment cards if the source code is not run through a preprocessor. The 3-D algorithm has presented a number of problems that simpler algorithms, such as 1-D hydrodynamics, did not exhibit. Problems in converting the serial code, originally written for a Cray 1, to a multitasking code are discussed, Autotasking of a rewritten version of the code is discussed. Timing results for subroutines and hot spots in the serial code are presented and suggestions for additional tools and debugging aids are given. Theoretical speedup results obtained from Amdahl's law and actual speedup results obtained on a dedicated machine are presented. Suggestions for designing large parallel codes are given. 8 refs., 13 figs.
- Research Organization:
- Los Alamos National Lab., NM (USA)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 7123009
- Report Number(s):
- LA-UR-88-1836; CONF-8805169-1; ON: DE88014456
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
990210* -- Supercomputers-- (1987-1989)
ALGORITHMS
COMPUTER ARCHITECTURE
COMPUTER CODES
COMPUTERS
CRAY COMPUTERS
DATA PROCESSING
DESIGN
FLUID MECHANICS
HYDRODYNAMICS
MATHEMATICAL LOGIC
MECHANICS
PARALLEL PROCESSING
PROCESSING
PROGRAMMING
TASK SCHEDULING
THREE-DIMENSIONAL CALCULATIONS