Subject: [OMPI users] Did you break MPI_Abort recently?
From: Mostyn Lewis (Mostyn.Lewis_at_[hidden])
Date: 2009-06-25 16:29:56
While using the BLACS test programs, I've seen that with recent SVN checkouts
(including todays) the MPI_Abort test left procs running. The last SVN I
have where it worked was 1.4a1r20936. By 1.4a1r21246 it fails.
Works O.K. in the standard 1.3.2 release.
A test program is below. GCC was used.
DM
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#include <math.h>
#include <mpi.h>
#define NUM_ITERS 100000
/* Prototype the function that we'll use below. */
static double f(double);
int
main(int argc, char *argv[])
{
int iter, rank, size, i;
int foo;
double PI25DT = 3.141592653589793238462643;
double mypi, pi, h, sum, x;
double startwtime = 0.0, endwtime;
int namelen;
char processor_name[MPI_MAX_PROCESSOR_NAME];
/* Normal MPI startup */
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Get_processor_name(processor_name, &namelen);
printf("Process %d of %d on %s\n", rank, size, processor_name);
/* Do approximations for 1 to 100 points */
/* sleep(5); */
for (iter = 2; iter < NUM_ITERS; ++iter) {
h = 1.0 / (double) iter;
sum = 0.0;
/* A slightly better approach starts from large i and works back */
if (rank == 0)
startwtime = MPI_Wtime();
for (i = rank + 1; i <= iter; i += size) {
x = h * ((double) i - 0.5);
sum += f(x);
}
mypi = h * sum;
if(iter == (NUM_ITERS - 1000)){
MPI_Barrier(MPI_COMM_WORLD);
if(rank == 2){
MPI_Abort(MPI_COMM_WORLD, -1);
} else {
/* Just loop */
foo = 1;
while(foo == 1){
foo = foo + 3;
foo = foo - 2;
foo = foo - 1;
}
}
}
MPI_Reduce(&mypi, &pi, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD);
}
/* All done */
if (rank == 0) {
printf("%d points: pi is approximately %.16f, error = %.16f\n",
iter, pi, fabs(pi - PI25DT));
endwtime = MPI_Wtime();
printf("wall clock time = %f\n", endwtime - startwtime);
fflush(stdout);
}
MPI_Finalize();
return 0;
}
static double
f(double a)
{
return (4.0 / (1.0 + a * a));
}