mpi_pi.reducer.c File Reference

Example for KMRRUN. More...

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <mpi.h>

Go to the source code of this file.

Macros
#define	LINELEN   80

Functions
int	main (int argc, char *argv[])
	Main function. More...

Detailed Description

Example for KMRRUN.

It is a reducer for PI calculation implemented using MPI.

How to run.

1. create input files in a directory. work/ 000 001 002 ...

   Each file have one line which represents number of points to plot. $ cat work/000 100000

2. run by kmrrun $ mpirun -np 2 ./kmrrun –mpi-proc 4 –m-mpi "./mpi_pi.mapper" \ -k "./mpi_pi.kvgen.sh" –r-mpi "./mpi_pi.reducer" ./work

Definition in file mpi_pi.reducer.c.

Function Documentation

int main	(	int	argc,
		char *	argv[]
	)

Main function.

Read a file which has key-values separated by lines. One line is like this.

0 7932/10000

'0' is key and '7932/10000' is value. 7932 is number of points plotted in a circle and 10000 is total number of points plotted. By reading these numbers, it calculates pi and writes result to a file.

Definition at line 43 of file mpi_pi.reducer.c.