/* * Copyright (C) 2001 * National Center for Supercomputing Applications * All rights reserved. * */ /* * Parallel HDF5 Performance Testing Code * -------------------------------------- * * Portable code to test performance on the different platforms we support. * This is what the report should look like: * * nprocs = Max#Procs * IO Type = Raw * # Files = 1, # of dsets = 1000, Elements per dset = 37000 * Write Results = x MB/s * Read Results = x MB/s * # Files = 1, # of dsets = 3000, Elements per dset = 37000 * Write Results = x MB/s * Read Results = x MB/s * * . . . * * IO Type = MPIO * # Files = 1, # of dsets = 1000, Elements per dset = 37000 * Write Results = x MB/s * Read Results = x MB/s * # Files = 1, # of dsets = 3000, Elements per dset = 37000 * Write Results = x MB/s * Read Results = x MB/s * * . . . * * IO Type = PHDF5 * # Files = 1, # of dsets = 1000, Elements per dset = 37000 * Write Results = x MB/s * Read Results = x MB/s * # Files = 1, # of dsets = 3000, Elements per dset = 37000 * Write Results = x MB/s * Read Results = x MB/s * * . . . * * nprocs = Max#Procs / 2 * * . . . * */ /* system header files */ #include #include #include #include "hdf5.h" #ifdef H5_HAVE_PARALLEL /* library header files */ #include /* our header files */ #include "h5tools_utils.h" #include "pio_perf.h" /* useful macros */ #define TAB_SPACE 4 #define ONE_KB 1024 #define ONE_MB (ONE_KB * ONE_KB) #define ONE_GB (ONE_MB * ONE_KB) #define PIO_RAW 0x10 #define PIO_MPI 0x20 #define PIO_HDF5 0x40 #define MB_PER_SEC(bytes,t) (((bytes) / ONE_MB) / t) #define MIN_HDF5_BUF_SIZE (ONE_MB >> 1) #define MAX_HDF5_BUF_SIZE (ONE_GB / 2) /* global variables */ MPI_Comm pio_comm_g; /* Communicator to run the PIO */ int pio_mpi_rank_g; /* MPI rank of pio_comm_g */ int pio_mpi_nprocs_g; /* number of processes of pio_comm_g */ /* local variables */ static const char *progname = "pio_perf"; /* * Command-line options: The user can specify short or long-named * parameters. The long-named ones can be partially spelled. When * adding more, make sure that they don't clash with each other. */ #if 1 static const char *s_opts = "hf:HP:p:X:x:md:F:i:o:r"; #else static const char *s_opts = "hbf:HP:p:X:x:md:F:i:o:r"; #endif /* 1 */ static struct long_options l_opts[] = { { "help", no_arg, 'h' }, { "hel", no_arg, 'h' }, { "he", no_arg, 'h' }, #if 0 /* a siting of the elusive binary option */ { "binary", no_arg, 'b' }, { "binar", no_arg, 'b' }, { "bina", no_arg, 'b' }, { "bin", no_arg, 'b' }, { "bi", no_arg, 'b' }, #endif /* 0 */ { "file-size", require_arg, 'f' }, { "file-siz", require_arg, 'f' }, { "file-si", require_arg, 'f' }, { "file-s", require_arg, 'f' }, { "file", require_arg, 'f' }, { "fil", require_arg, 'f' }, { "fi", require_arg, 'f' }, { "hdf5", no_arg, 'H' }, { "hdf", no_arg, 'H' }, { "hd", no_arg, 'H' }, { "max-num-processes", require_arg, 'P' }, { "max-num-processe", require_arg, 'P' }, { "max-num-process", require_arg, 'P' }, { "max-num-proces", require_arg, 'P' }, { "max-num-proce", require_arg, 'P' }, { "max-num-proc", require_arg, 'P' }, { "max-num-pro", require_arg, 'P' }, { "max-num-pr", require_arg, 'P' }, { "max-num-p", require_arg, 'P' }, { "min-num-processes", require_arg, 'p' }, { "min-num-processe", require_arg, 'p' }, { "min-num-process", require_arg, 'p' }, { "min-num-proces", require_arg, 'p' }, { "min-num-proce", require_arg, 'p' }, { "min-num-proc", require_arg, 'p' }, { "min-num-pro", require_arg, 'p' }, { "min-num-pr", require_arg, 'p' }, { "min-num-p", require_arg, 'p' }, { "max-xfer-size", require_arg, 'X' }, { "max-xfer-siz", require_arg, 'X' }, { "max-xfer-si", require_arg, 'X' }, { "max-xfer-s", require_arg, 'X' }, { "max-xfer", require_arg, 'X' }, { "max-xfe", require_arg, 'X' }, { "max-xf", require_arg, 'X' }, { "max-x", require_arg, 'X' }, { "min-xfer-size", require_arg, 'x' }, { "min-xfer-siz", require_arg, 'x' }, { "min-xfer-si", require_arg, 'x' }, { "min-xfer-s", require_arg, 'x' }, { "min-xfer", require_arg, 'x' }, { "min-xfe", require_arg, 'x' }, { "min-xf", require_arg, 'x' }, { "min-x", require_arg, 'x' }, { "mpiio", no_arg, 'm' }, { "mpii", no_arg, 'm' }, { "mpi", no_arg, 'm' }, { "mp", no_arg, 'm' }, { "num-dsets", require_arg, 'd' }, { "num-dset", require_arg, 'd' }, { "num-dse", require_arg, 'd' }, { "num-ds", require_arg, 'd' }, { "num-d", require_arg, 'd' }, { "num-files", require_arg, 'F' }, { "num-file", require_arg, 'F' }, { "num-fil", require_arg, 'F' }, { "num-fi", require_arg, 'F' }, { "num-f", require_arg, 'F' }, { "num-iterations", require_arg, 'i' }, { "num-iteration", require_arg, 'i' }, { "num-iteratio", require_arg, 'i' }, { "num-iterati", require_arg, 'i' }, { "num-iterat", require_arg, 'i' }, { "num-itera", require_arg, 'i' }, { "num-iter", require_arg, 'i' }, { "num-ite", require_arg, 'i' }, { "num-it", require_arg, 'i' }, { "num-i", require_arg, 'i' }, { "output", require_arg, 'o' }, { "outpu", require_arg, 'o' }, { "outp", require_arg, 'o' }, { "out", require_arg, 'o' }, { "ou", require_arg, 'o' }, { "raw", no_arg, 'r' }, { "ra", no_arg, 'r' }, { NULL, 0, '\0' } }; struct options { long io_types; /* bitmask of which I/O types to test */ const char *output_file; /* file to print report to */ long file_size; /* size of file */ long num_dsets; /* number of datasets */ long num_files; /* number of files */ long num_iters; /* number of iterations */ long max_num_procs; /* maximum number of processes to use */ long min_num_procs; /* minimum number of processes to use */ long max_xfer_size; /* maximum transfer buffer size */ long min_xfer_size; /* minimum transfer buffer size */ }; typedef struct _minmax { double min; double max; double sum; int num; } minmax; /* local functions */ static long parse_size_directive(const char *size); static struct options *parse_command_line(int argc, char *argv[]); static void run_test_loop(FILE *output, struct options *options); static int run_test(FILE *output, iotype iot, parameters parms); static void get_minmax(minmax *mm); static minmax accumulate_minmax_stuff(minmax *mm, int count); static int create_comm_world(int num_procs, int *doing_pio); static int destroy_comm_world(void); static void output_report(FILE *output, const char *fmt, ...); static void print_indent(register FILE *output, register int indent); static void usage(const char *prog); /* * Function: main * Purpose: Start things up. Initialize MPI and then call the test looping * function. * Return: EXIT_SUCCESS or EXIT_FAILURE * Programmer: Bill Wendling, 30. October 2001 * Modifications: */ int main(int argc, char **argv) { int world_size, ret; int exit_value = EXIT_SUCCESS; FILE *output = stdout; struct options *opts = NULL; /* initialize MPI and get the maximum num of processors we started with */ MPI_Init(&argc, &argv); ret = MPI_Comm_size(MPI_COMM_WORLD, &world_size); if (ret != MPI_SUCCESS) { fprintf(stderr, "%s: MPI_Comm_size call failed\n", progname); if (ret == MPI_ERR_COMM) fprintf(stderr, "invalid MPI communicator\n"); else fprintf(stderr, "invalid argument\n"); exit_value = EXIT_FAILURE; goto finish; } pio_comm_g = MPI_COMM_WORLD; opts = parse_command_line(argc, argv); if (!opts) { exit_value = EXIT_FAILURE; goto finish; } if (opts->output_file) { if ((output = fopen(opts->output_file, "w")) == NULL) { fprintf(stderr, "%s: cannot open output file\n", progname); perror(opts->output_file); goto finish; } } run_test_loop(output, opts); finish: MPI_Finalize(); free(opts); return exit_value; } /* * Function: run_test_loop * Purpose: Run the I/O tests. Write the results to OUTPUT. * * - The slowest changing part of the test is the number of * processors to use. For each loop iteration, we divide that * number by 2 and rerun the test. * * - The second slowest is what type of IO to perform. We have * three choices: RAW, MPI-IO, and PHDF5. * * - Then we change the size of the buffer. This information is * inferred from the number of datasets to create and the number * of integers to put into each dataset. The backend code figures * this out. * * Return: Nothing * Programmer: Bill Wendling, 30. October 2001 * Modifications: */ static void run_test_loop(FILE *output, struct options *opts) { parameters parms; long num_procs; int doing_pio; /* if this process is doing PIO */ int io_runs = PIO_HDF5 | PIO_MPI | PIO_RAW; /* default to run all tests */ if (opts->io_types & ~0x7) { /* we want to run only a select subset of these tests */ io_runs = 0; if (opts->io_types & PIO_HDF5) io_runs |= PIO_HDF5; if (opts->io_types & PIO_MPI) io_runs |= PIO_MPI; if (opts->io_types & PIO_RAW) io_runs |= PIO_RAW; } parms.num_files = opts->num_files; parms.num_dsets = opts->num_dsets; parms.num_iters = opts->num_iters; /* multiply the maximum number of processors by 2 for each loop iter */ for (num_procs = opts->min_num_procs; num_procs <= opts->max_num_procs; num_procs <<= 1) { register long buf_size; parms.num_procs = num_procs; if (create_comm_world(parms.num_procs, &doing_pio) != SUCCESS) { /* do something harsh */ } /* only processes doing PIO will run the tests */ if (doing_pio){ output_report(output, "Number of processors = %ld\n", parms.num_procs); /* multiply the xfer buffer size by 2 for each loop iteration */ for (buf_size = opts->min_xfer_size; buf_size <= opts->max_xfer_size; buf_size <<= 1) { parms.buf_size = buf_size; parms.num_elmts = opts->file_size / (parms.num_dsets * sizeof(int)); print_indent(output, TAB_SPACE * 1); output_report(output, "Transfer Buffer Size: %ld\n", buf_size); print_indent(output, TAB_SPACE * 1); output_report(output, " # of files: %ld, # of dsets: %ld, # of elmts per dset: %ld\n", parms.num_files, parms.num_dsets, parms.num_elmts); if (io_runs & PIO_RAW) run_test(output, RAW, parms); if (io_runs & PIO_MPI) run_test(output, MPIO, parms); if (io_runs & PIO_HDF5) run_test(output, PHDF5, parms); } if (destroy_comm_world() != SUCCESS) { /* do something harsh */ } } } } /* * Function: run_test * Purpose: Inner loop call to actually run the I/O test. * Return: Nothing * Programmer: Bill Wendling, 18. December 2001 * Modifications: */ static int run_test(FILE *output, iotype iot, parameters parms) { results res; register int i, ret_value = SUCCESS; int comm_size; long raw_size; minmax total_mm; minmax *write_mm_table; minmax *read_mm_table; minmax write_mm = {0.0, 0.0, 0.0, 0}; minmax read_mm = {0.0, 0.0, 0.0, 0}; raw_size = parms.num_dsets * parms.num_elmts * sizeof(int); parms.io_type = iot; print_indent(output, TAB_SPACE * 2); output_report(output, "Type of IO = "); switch (iot) { case RAW: output_report(output, "Raw\n"); break; case MPIO: output_report(output, "MPIO\n"); break; case PHDF5: output_report(output, "PHDF5\n"); break; } MPI_Comm_size(pio_comm_g, &comm_size); write_mm_table = malloc(parms.num_iters * sizeof(minmax)); read_mm_table = malloc(parms.num_iters * sizeof(minmax)); for (i = 0; i < parms.num_iters; ++i) { write_mm_table[i].min = 0.0; write_mm_table[i].max = 0.0; write_mm_table[i].sum = 0.0; write_mm_table[i].num = 0; read_mm_table[i].min = 0.0; read_mm_table[i].max = 0.0; read_mm_table[i].sum = 0.0; read_mm_table[i].num = 0; } /* call Albert's testing here */ for (i = 0; i < parms.num_iters; ++i) { register int j; double t; MPI_Barrier(pio_comm_g); res = do_pio(parms); t = get_time(res.timers, HDF5_GROSS_WRITE_FIXED_DIMS); MPI_Send((void *)&t, 1, MPI_DOUBLE, 0, 0, pio_comm_g); for (j = 0; j < comm_size; ++j) get_minmax(&write_mm); write_mm_table[i] = write_mm; t = get_time(res.timers, HDF5_GROSS_READ_FIXED_DIMS); MPI_Send((void *)&t, 1, MPI_DOUBLE, 0, 0, pio_comm_g); for (j = 0; j < comm_size; ++j) get_minmax(&read_mm); read_mm_table[i] = read_mm; } total_mm = accumulate_minmax_stuff(write_mm_table, parms.num_iters); print_indent(output, TAB_SPACE * 3); output_report(output, "Write (%d iterations):\n", parms.num_iters); print_indent(output, TAB_SPACE * 4); output_report(output, "Minimum Time: %.2fs (%.2f MB/s)\n", total_mm.min, MB_PER_SEC(raw_size, total_mm.min)); print_indent(output, TAB_SPACE * 4); output_report(output, "Maximum Time: %.2fs (%.2f MB/s)\n", total_mm.max, MB_PER_SEC(raw_size, total_mm.max)); print_indent(output, TAB_SPACE * 4); output_report(output, "Average Time: %.2fs (%.2f MB/s)\n", total_mm.sum / total_mm.num, MB_PER_SEC(raw_size, (total_mm.sum / total_mm.num))); total_mm = accumulate_minmax_stuff(read_mm_table, parms.num_iters); print_indent(output, TAB_SPACE * 3); output_report(output, "Read (%d iterations):\n", parms.num_iters); print_indent(output, TAB_SPACE * 4); output_report(output, "Minimum Time: %.2fs (%.2f MB/s)\n", total_mm.min, MB_PER_SEC(raw_size, total_mm.min)); print_indent(output, TAB_SPACE * 4); output_report(output, "Maximum Time: %.2fs (%.2f MB/s)\n", total_mm.max, MB_PER_SEC(raw_size, total_mm.max)); print_indent(output, TAB_SPACE * 4); output_report(output, "Average Time: %.2fs (%.2f MB/s)\n", total_mm.sum / total_mm.num, MB_PER_SEC(raw_size, (total_mm.sum / total_mm.num))); free(write_mm_table); free(read_mm_table); pio_time_destroy(res.timers); return ret_value; } /* * Function: get_minmax_stuff * Purpose: Each process sends its MINMAX information to the 0 process. * If we're the 0 process, we gather that information. * Return: Nothing * Programmer: Bill Wendling, 21. December 2001 * Modifications: */ static void get_minmax(minmax *mm) { int myrank; MPI_Comm_rank(pio_comm_g, &myrank); if (myrank == 0) { MPI_Status status = {0}; double t; MPI_Recv((void *)&t, 1, MPI_DOUBLE, MPI_ANY_SOURCE, MPI_ANY_TAG, pio_comm_g, &status); ++mm->num; mm->sum += t; if (t > mm->max) mm->max = t; if (t < mm->min || mm->min <= 0.0) mm->min = t; } } /* * Function: accumulate_minmax_stuff * Purpose: Accumulate the minimum, maximum, and average of the times * across all processes. * Return: TOTAL_MM - the total of all of these. * Programmer: Bill Wendling, 21. December 2001 * Modifications: */ static minmax accumulate_minmax_stuff(minmax *mm, int count) { register int i; minmax total_mm = mm[0]; for (i = 1; i < count; ++i) { total_mm.sum += mm[i].sum; total_mm.num += mm[i].num; if (mm[i].min < total_mm.min) total_mm.min = mm[i].min; if (mm[i].max > total_mm.max) total_mm.max = mm[i].max; } return total_mm; } /* * Function: create_comm_world * Purpose: Create an MPI Comm world and store it in pio_comm_g, which * is a global variable. * Return: SUCCESS on success. * FAIL otherwise. * Programmer: Bill Wendling, 19. December 2001 * Modifications: */ static int create_comm_world(int num_procs, int *doing_pio) { /* MPI variables */ int mrc, ret_value; /* return values */ int color; /* for communicator creation */ int myrank, nprocs; pio_comm_g = MPI_COMM_NULL; /* * Create a sub communicator for this PIO run. Easier to use the first N * processes. */ MPI_Comm_size(MPI_COMM_WORLD, &nprocs); if (num_procs > nprocs) { fprintf(stderr, "number of process(%d) must be <= number of processes in MPI_COMM_WORLD(%d)\n", num_procs, nprocs); goto error_done; } MPI_Comm_rank(MPI_COMM_WORLD, &myrank); color = (myrank < num_procs); mrc = MPI_Comm_split(MPI_COMM_WORLD, color, myrank, &pio_comm_g); if (mrc != MPI_SUCCESS) { fprintf(stderr, "MPI_Comm_split failed\n"); goto error_done; } if (!color) { /* not involved in this run */ mrc = destroy_comm_world(); goto done; } /* determine the MPI rank in the PIO communicator */ MPI_Comm_size(pio_comm_g, &pio_mpi_nprocs_g); MPI_Comm_rank(pio_comm_g, &pio_mpi_rank_g); done: *doing_pio = color; return ret_value; error_done: destroy_comm_world(); return FAIL; } /* * Function: destroy_comm_world * Purpose: Destroy the created MPI Comm world which is stored in the * pio_comm_g global variable. * Return: SUCCESS on success. * FAIL otherwise. * Programmer: Bill Wendling, 19. December 2001 * Modifications: */ static int destroy_comm_world(void) { int mrc = SUCCESS; /* return code */ /* release MPI resources */ if (pio_comm_g != MPI_COMM_NULL) mrc = (MPI_Comm_free(&pio_comm_g) == MPI_SUCCESS ? SUCCESS : FAIL); return mrc; } /* * Function: output_report * Purpose: Print a line of the report. Only do so if I'm the 0 process. * Return: Nothing * Programmer: Bill Wendling, 19. December 2001 * Modifications: */ static void output_report(FILE *output, const char *fmt, ...) { int myrank; MPI_Comm_rank(pio_comm_g, &myrank); if (myrank == 0) { va_list ap; va_start(ap, fmt); vfprintf(output, fmt, ap); va_end(ap); } } /* * Function: print_indent * Purpose: Print spaces to indent a new line of text for pretty printing * things. * Return: Nothing * Programmer: Bill Wendling, 29. October 2001 * Modifications: */ static void print_indent(register FILE *output, register int indent) { for (; indent > 0; --indent) fputc(' ', output); } /* * Function: parse_command_line * Purpose: Parse the command line options and return a STRUCT OPTIONS * structure which will need to be freed by the calling function. * Return: Pointer to an OPTIONS structure * Programmer: Bill Wendling, 31. October 2001 * Modifications: */ static struct options * parse_command_line(int argc, char *argv[]) { register int opt; struct options *cl_opts; cl_opts = (struct options *)malloc(sizeof(struct options)); cl_opts->output_file = NULL; cl_opts->file_size = 64 * ONE_MB; cl_opts->io_types = 0x7; /* bottom bits indicate default type to run */ cl_opts->num_dsets = 1; cl_opts->num_files = 1; cl_opts->num_iters = 1; cl_opts->max_num_procs = 1; cl_opts->min_num_procs = 1; cl_opts->max_xfer_size = 1 * ONE_MB; cl_opts->min_xfer_size = 1 * ONE_KB; while ((opt = get_option(argc, (const char **)argv, s_opts, l_opts)) != EOF) { switch ((char)opt) { #if 0 case 'b': /* the future "binary" option */ break; #endif /* 0 */ case 'd': cl_opts->num_dsets = strtol(opt_arg, NULL, 10); break; case 'f': cl_opts->file_size = parse_size_directive(opt_arg); break; case 'F': cl_opts->num_files = strtol(opt_arg, NULL, 10); break; case 'H': cl_opts->io_types &= ~0x7; cl_opts->io_types |= PIO_HDF5; break; case 'i': cl_opts->num_iters = strtol(opt_arg, NULL, 10); break; case 'm': cl_opts->io_types &= ~0x7; cl_opts->io_types |= PIO_MPI; break; case 'o': cl_opts->output_file = opt_arg; break; case 'p': cl_opts->min_num_procs = strtol(opt_arg, NULL, 10); break; case 'P': cl_opts->max_num_procs = strtol(opt_arg, NULL, 10); break; case 'r': cl_opts->io_types &= ~0x7; cl_opts->io_types |= PIO_RAW; break; case 'x': cl_opts->min_xfer_size = parse_size_directive(opt_arg); break; case 'X': cl_opts->max_xfer_size = parse_size_directive(opt_arg); break; case 'h': case '?': default: usage(progname); free(cl_opts); return NULL; } } return cl_opts; } /* * Function: parse_size_directive * Purpose: Parse the size directive passed on the commandline. The size * directive is an integer followed by a size indicator: * * K, k - Kilobyte * M, m - Megabyte * G, g - Gigabyte * * Return: The size as a LONG. If an unknown size indicator is used, then * the program will exit with EXIT_FAILURE as the return value. * Programmer: Bill Wendling, 18. December 2001 * Modifications: */ static long parse_size_directive(const char *size) { long s; char *endptr; s = strtol(size, &endptr, 10); if (endptr && *endptr) { while (*endptr != '\0' && (*endptr == ' ' || *endptr == '\t')) ++endptr; switch (*endptr) { case 'K': case 'k': s *= ONE_KB; break; case 'M': case 'm': s *= ONE_MB; break; case 'G': case 'g': s *= ONE_GB; break; default: fprintf(stderr, "Illegal size specifier '%c'\n", *endptr); exit(EXIT_FAILURE); } } return s; } /* * Function: usage * Purpose: Print a usage message and then exit. * Return: Nothing * Programmer: Bill Wendling, 31. October 2001 * Modifications: */ static void usage(const char *prog) { int myrank; MPI_Comm_rank(pio_comm_g, &myrank); if (myrank == 0) { fflush(stdout); fprintf(stdout, "usage: %s [OPTIONS]\n", prog); fprintf(stdout, " OPTIONS\n"); fprintf(stdout, " -h, --help Print a usage message and exit\n"); fprintf(stdout, " -d N, --num-dsets=N Number of datasets per file [default:1]\n"); fprintf(stdout, " -f S, --file-size=S Size of a single file [default: 64M]\n"); fprintf(stdout, " -F N, --num-files=N Number of files [default: 1]\n"); fprintf(stdout, " -H, --hdf5 Run HDF5 performance test\n"); fprintf(stdout, " -i, --num-iterations Number of iterations to perform [default: 1]\n"); fprintf(stdout, " -m, --mpiio Run MPI/IO performance test\n"); fprintf(stdout, " -o F, --output=F Output raw data into file F [default: none]\n"); fprintf(stdout, " -P N, --max-num-processes=N Maximum number of processes to use [default: 1]\n"); fprintf(stdout, " -p N, --min-num-processes=N Minimum number of processes to use [default: 1]\n"); fprintf(stdout, " -r, --raw Run raw (UNIX) performance test\n"); fprintf(stdout, " -X S, --max-xfer-size=S Maximum transfer buffer size [default: 1M]\n"); fprintf(stdout, " -x S, --min-xfer-size=S Minimum transfer buffer size [default: 1K]\n"); fprintf(stdout, "\n"); fprintf(stdout, " F - is a filename.\n"); fprintf(stdout, " N - is an integer >=0.\n"); fprintf(stdout, " S - is a size specifier, an integer >=0 followed by a size indicator:\n"); fprintf(stdout, "\n"); fprintf(stdout, " K - Kilobyte\n"); fprintf(stdout, " M - Megabyte\n"); fprintf(stdout, " G - Gigabyte\n"); fprintf(stdout, "\n"); fprintf(stdout, " Example: 37M = 37 Megabytes\n"); fprintf(stdout, "\n"); fflush(stdout); } } #else /* H5_HAVE_PARALLEL */ /* * Function: main * Purpose: Dummy main() function for if HDF5 was configured without * parallel stuff. * Return: EXIT_SUCCESS * Programmer: Bill Wendling, 14. November 2001 * Modifications: */ int main(void) { printf("No parallel IO performance because parallel is not configured\n"); return EXIT_SUCCESS; } #endif /* !H5_HAVE_PARALLEL */