createmany-mpi.c

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdarg.h>

#include "mpi.h"

void usage(char *prog)
{
	printf("usage: %s {-o|-m} filenamefmt count\n", prog);
	printf("       %s {-o|-m} filenamefmt -seconds\n", prog);
	printf("       %s {-o|-m} filenamefmt start count\n", prog);
}

/* Print process rank, loop count, message, and exit (i.e. a fatal error) */
int rprintf(int rank, int loop, const char *fmt, ...)
{
        va_list       ap;

        printf("rank %d, loop %d: ", rank, loop);

        va_start(ap, fmt);

        printf(fmt, ap);

        MPI_Finalize();
        exit(1);
}

int main(int argc, char ** argv)
{
        int i, rc = 0, do_open, rank;
        char format[4096], *fmt;
        char filename[4096];
        long start, last, end;
	long begin = 0, count;

        rc = MPI_Init(&argc, &argv);
        if (rc != MPI_SUCCESS)
                rprintf(-1, -1, "MPI_Init failed: %d\n", rc);

        if (argc < 4 || argc > 5) {
		usage(argv[0]);
                return 1;
        }

        if (strcmp(argv[1], "-o") == 0) {
                do_open = 1;
        } else if (strcmp(argv[1], "-m") == 0) {
                do_open = 0;
        } else {
		usage(argv[0]);
                return 1;
        }

        if (strlen(argv[2]) > 4080) {
                printf("name too long\n");
                return 1;
        }

        rc = MPI_Comm_rank(MPI_COMM_WORLD, &rank);
        if (rc != MPI_SUCCESS)
                rprintf(-1, -1, "MPI_Comm_rank failed: %d\n", rc);

        rc = MPI_Barrier(MPI_COMM_WORLD);
        if (rc != MPI_SUCCESS)
                rprintf(rank, -1, "prep MPI_Barrier failed: %d\n", rc);

        start = last = time(0);

	if (argc == 4) {
		end = strtol(argv[3], NULL, 0);
		if (end > 0) {
			count = end;
			end = -1UL >> 1;
		} else {
			end = start - end;
			count = -1UL >> 1;
		}
	} else {
		end = -1UL >> 1;
		begin = strtol(argv[3], NULL, 0);
		count = strtol(argv[4], NULL, 0);
	}

	if (strchr(argv[2], '%'))
		fmt = argv[2];
	else {
		sprintf(format, "%s%%d", argv[2]);
		fmt = format;
	}
	printf("starting at %s", ctime(&start));
        for (i = 0; i < count && time(0) < end; i++, begin++) {
                sprintf(filename, fmt, begin);
                if (do_open) {
                        int fd = open(filename, O_CREAT|O_RDWR, 0644);
                        if (fd < 0) {
                                printf("open(%s) error: %s\n", filename,
                                       strerror(errno));
                                rc = errno;
                                break;
                        }
                        close(fd);
                } else {
                        rc = mknod(filename, S_IFREG| 0444, 0);
                        if (rc) {
                                printf("mknod(%s) error: %s\n",
                                       filename, strerror(errno));
                                rc = errno;
                                break;
                        }
                }
                if ((i % 10000) == 0) {
                        printf(" - created %d (time %ld ; total %ld ; last %ld)\n",
                               i, time(0), time(0) - start, time(0) - last);
                        last = time(0);
                }
        }
        printf("total: %d creates in %ld seconds: %f creates/second\n", i,
               time(0) - start, ((float)i / (time(0) - start)));
	start = time(0);
	printf("finish at %s", ctime(&start));

        return rc;
}