write_disjoint.c 8.66 KiB
/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=8:tabstop=8:
*
* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is included
* in the LICENSE file that accompanied this code).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; If not, see
* http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
* GPL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved
* Use is subject to license terms.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* Lustre is a trademark of Sun Microsystems, Inc.
*
* lustre/tests/write_disjoint.c
*
* Each loop does 3 things:
* - rank 0 truncates to 0
* - all ranks agree on a random chunk size
* - all ranks race to write their pattern to their chunk of the file
* - rank 0 makes sure that the resulting file size is ranks * chunk size
* - rank 0 makes sure that everyone's patterns went to the right place
*
* compile: mpicc -g -Wall -o write_disjoint write_disjoint.c
* run: mpirun -np N -machlist <hostlist file> write_disjoint
* or: pdsh -w <N hosts> write_disjoint
* or: prun -n N [-N M] write_disjoint
*/
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <stdarg.h>
#include "mpi.h"
#define CHUNK_MAX_SIZE 123456
void rprintf(int rank, int loop, const char *fmt, ...)
{
va_list ap;
printf("rank %d, loop %d: ", rank, loop);
va_start(ap, fmt);
vprintf(fmt, ap);
MPI_Abort(MPI_COMM_WORLD, -1); /* This will exit() according to man */
}
#define CHUNK_SIZE(n) chunk_size[(n) % 2]
int main (int argc, char *argv[]) {
int i, n, fd;
unsigned long chunk_size[2];
int rank, noProcessors, done;
int error;
off_t offset;
char **chunk_buf;
char *read_buf, c;
struct stat stat_buf;
ssize_t ret;
char *filename = "/mnt/lustre/write_disjoint";
int numloops = 1000;
error = MPI_Init(&argc, &argv);
if (error != MPI_SUCCESS)
rprintf(-1, -1, "MPI_Init failed: %d\n", error);
/* Parse command line options */
while ((c = getopt(argc, argv, "f:n:")) != EOF) {
switch (c) {
case 'f':
filename = optarg;
break;
case 'n':
numloops = strtoul(optarg, NULL, 0);
break;
}
}
MPI_Comm_size(MPI_COMM_WORLD, &noProcessors);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
chunk_buf = malloc(noProcessors * sizeof(chunk_buf[0]));
for (i=0; i < noProcessors; i++) {
chunk_buf[i] = malloc(CHUNK_MAX_SIZE);
memset(chunk_buf[i], 'A'+ i, CHUNK_MAX_SIZE);
}
read_buf = malloc(noProcessors * CHUNK_MAX_SIZE);
if (rank == 0) {
fd = open(filename, O_WRONLY|O_CREAT|O_TRUNC, 0666);
if (fd < 0)
rprintf(rank, -1, "open() returned %s\n",
strerror(errno));
}
MPI_Barrier(MPI_COMM_WORLD);
fd = open(filename, O_RDWR);
if (fd < 0)
rprintf(rank, -1, "open() returned %s\n", strerror(errno));
for (n = 0; n < numloops; n++) {
/* reset the environment */
if (rank == 0) {
ret = truncate(filename, 0);
if (ret != 0)
rprintf(rank, n, "truncate() returned %s\n",
strerror(errno) );
}
CHUNK_SIZE(n) = rand() % CHUNK_MAX_SIZE;
if (n % 1000 == 0 && rank == 0)
printf("loop %d: chunk_size %lu\n", n, CHUNK_SIZE(n));
MPI_Barrier(MPI_COMM_WORLD);
/* Do the race */
offset = rank * CHUNK_SIZE(n);
lseek(fd, offset, SEEK_SET);
done = 0;
do {
ret = write(fd, chunk_buf[rank] + done,
CHUNK_SIZE(n) - done);
if (ret < 0)
rprintf(rank, n, "write() returned %s\n",
strerror(errno));
done += ret;
} while (done != CHUNK_SIZE(n));
MPI_Barrier(MPI_COMM_WORLD);
/* Check the result */
if (stat(filename, &stat_buf) < 0)
rprintf(rank, n, "error stating %s: %s\n",
filename, strerror(errno));
if (stat_buf.st_size != CHUNK_SIZE(n) * noProcessors) {
if (n > 0)
printf("loop %d: chunk_size %lu, "
"file size was %lu\n",
n - 1, CHUNK_SIZE(n - 1),
CHUNK_SIZE(n - 1) *noProcessors);
rprintf(rank, n, "invalid file size %lu"
" instead of %lu = %lu * %u\n",
(unsigned long)stat_buf.st_size,
CHUNK_SIZE(n) * noProcessors,
CHUNK_SIZE(n), noProcessors);
}
if (rank == 0) {
if (lseek(fd, 0, SEEK_SET) < 0)
rprintf(rank, n, "error seeking to 0: %s\n",
strerror(errno));
done = 0;
do {
ret = read(fd, read_buf + done,
CHUNK_SIZE(n) * noProcessors - done);
if (ret < 0)
rprintf(rank, n, "read returned %s\n",
strerror(errno));
done += ret;
} while (done != CHUNK_SIZE(n) * noProcessors);
for (i = 0; i < noProcessors; i++) {
char command[4096];
int j;
if (!memcmp(read_buf + (i * CHUNK_SIZE(n)),
chunk_buf[i], CHUNK_SIZE(n)))
continue;
/* print out previous chunk sizes */
if (n > 0)
printf("loop %d: chunk_size %lu\n",
n - 1, CHUNK_SIZE(n - 1));
printf("loop %d: chunk %d corrupted "
"with chunk_size %lu, page_size %d\n",
n, i, CHUNK_SIZE(n), getpagesize());
printf("ranks:\tpage boundry\tchunk boundry\t"
"page boundry\n"); for (j = 1 ; j < noProcessors; j++) {
int b = j * CHUNK_SIZE(n);
printf("%c -> %c:\t%d\t%d\t%d\n",
'A' + j - 1, 'A' + j,
b & ~(getpagesize()-1), b,
(b + getpagesize()) &
~(getpagesize()-1));
}
sprintf(command, "od -Ad -a %s", filename);
system(command);
rprintf(0, n, "data check error - exiting\n");
}
}
}
printf("Finished after %d loops\n", n);
MPI_Finalize();
return 0;
}