Synergy User Manual and Tutorial. - THE CORE MEMORY

Synergy User Manual and Tutorial
supercomputing, after performance, is cost efficiency. The third fastest supercomputing
cluster is the 17.6 TFlop System X at Virginia Tech. It consists of 1100 dual processor
Apple Power Macintosh G5s running Mac OS X. It cost a mere $5.2 million, which is 10
percent of the cost of much slower mainframe supercomputers.
The Parallel Virtual Machine (PVM)
The Parallel Virtual Machine (PVM), a software tool to implement a system of
networked parallel computers, was originally developed by Oak Ridge National
Laboratory (ORNL) in 1989 by Vaidy Sunderam and Al Geist. Version 1 was a
prototype that was only used internally for research .PVM was later rewritten by
University of Tennessee and released as Version 2 in 1991, which was used primarily for
scientific applications. PVM Version 3, completed in 1993, supported fault tolerance and
provided better portability. This system supports C, C++ and Fortran programming
languages.
PVM allows a heterogeneous network of machines to function as a single distributed
parallel processor. This system uses message-passing model as a means to implement the
sharing of tasks between machines. Programmers use PVM’s message passing to take
advantage of the computational power of possibly many computers of various types in a
distributed system, making them appear to be one virtual machine. PVM’s API has a
collection of functions to facilitate parallel programming by message passing. To spawn
workers, the pvm_spawn() function is called:
int status = pvm_spawn(char* task, char** argv, int flag, char* where, int
ntask, int* tid);
where status is an integer that holds the number of tasks successfully spawned, task is the
name of the executable to start, argv is the arguments for the task program, flag is an
integer that specifies PVM options, where is the identifier of a host or system in which to
start a process, ntask is an integer holding the number of task processes to start, and tid is
an array to hold the task process ID’s. To end another task process, use the pvm_kill()
function:
int status = pvm_kill(int tid)
where status contains information about the operation, and tid is the task process number
to kill. To end the calling task, use the pvm_exit() function:
int status = pvm_exit();
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