diff options
Diffstat (limited to 'testpar/t_mpi.c')
| -rw-r--r-- | testpar/t_mpi.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/testpar/t_mpi.c b/testpar/t_mpi.c index 2b5a4e3..7b34119 100644 --- a/testpar/t_mpi.c +++ b/testpar/t_mpi.c @@ -371,6 +371,156 @@ finish: /* + * MPI-IO Test: One writes, Many reads. + * Verify if only one process writes some data and then all other + * processes can read them back correctly. This tests if the + * underlaying parallel I/O and file system supports parallel I/O + * correctly. + * + * Algorithm: Only one process (e.g., process 0) writes some data. + * Then all processes, including the writing process, read the data + * back and verify them against the original values. + */ + +/* + * Default filename can be specified via first program argument. + * Each process writes something, then reads all data back. + */ + +#define DIMSIZE 32 /* Dimension size. */ +#define PRINTID printf("Proc %d: ", mpi_rank) +#define USENONE 0 +#define USEATOM 1 /* request atomic I/O */ +#define USEFSYNC 2 /* request file_sync */ + + +test_mpio_1wMr(char *filename, int special_request) +{ + char hostname[128]; + int mpi_size, mpi_rank; + MPI_File fh; + char mpi_err_str[MPI_MAX_ERROR_STRING]; + int mpi_err_strlen; + int mpi_err; + unsigned char writedata[DIMSIZE], readdata[DIMSIZE]; + unsigned char expect_val; + int i, irank; + int nerrors = 0; /* number of errors */ + MPI_Offset mpi_off; + MPI_Status mpi_stat; + + MPI_Comm_size(MPI_COMM_WORLD, &mpi_size); + MPI_Comm_rank(MPI_COMM_WORLD, &mpi_rank); + + if (mpi_rank==0){ + printf("Testing one process writes, all processes read.\n"); + printf("Using %d processes accessing file %s\n", mpi_size, filename); + printf(" (Filename can be specified via program argument)\n"); + } + + /* show the hostname so that we can tell where the processes are running */ + if (gethostname(hostname, 128) < 0){ + PRINTID; + printf("gethostname failed\n"); + return 1; + } + PRINTID; + printf("hostname=%s\n", hostname); + + /* Delete any old file in order to start anew. */ + /* Must delete because MPI_File_open does not have a Truncate mode. */ + /* Don't care if it has error. */ + MPI_File_delete(filename, MPI_INFO_NULL); + + if ((mpi_err = MPI_File_open(MPI_COMM_WORLD, filename, + MPI_MODE_RDWR | MPI_MODE_CREATE , + MPI_INFO_NULL, &fh)) + != MPI_SUCCESS){ + MPI_Error_string(mpi_err, mpi_err_str, &mpi_err_strlen); + PRINTID; + printf("MPI_File_open failed (%s)\n", mpi_err_str); + return 1; + } + + /* This barrier is not necessary but do it anyway. */ + MPI_Barrier(MPI_COMM_WORLD); + PRINTID; + printf("between MPI_Barrier and MPI_File_write_at\n"); + + /* ================================================== + * Each process calculates what to write but + * only process irank(0) writes. + * ==================================================*/ + irank=0; + for (i=0; i < DIMSIZE; i++) + writedata[i] = irank*DIMSIZE + i; + mpi_off = irank*DIMSIZE; + + /* Only one process writes */ + if (mpi_rank==irank){ + PRINTID; printf("wrote %d bytes at %d\n", DIMSIZE, mpi_off); + if ((mpi_err = MPI_File_write_at(fh, mpi_off, writedata, DIMSIZE, + MPI_BYTE, &mpi_stat)) + != MPI_SUCCESS){ + MPI_Error_string(mpi_err, mpi_err_str, &mpi_err_strlen); + PRINTID; + printf("MPI_File_write_at offset(%ld), bytes (%d), failed (%s)\n", + (long) mpi_off, (int) DIMSIZE, mpi_err_str); + return 1; + }; + }; + + /* Bcast the return code and */ + /* make sure all writing are done before reading. */ + MPI_Bcast(&mpi_err, 1, MPI_INT, irank, MPI_COMM_WORLD); + PRINTID; + printf("MPI_Bcast: mpi_err = %d\n", mpi_err); + + /* This barrier is not necessary because the Bcase above */ + /* should take care of it. Do it anyway. */ + MPI_Barrier(MPI_COMM_WORLD); + PRINTID; + printf("after MPI_Barrier\n"); + + /* ================================================== + * Each process reads what process 0 wrote and verify. + * ==================================================*/ + irank=0; + mpi_off = irank*DIMSIZE; + if ((mpi_err = MPI_File_read_at(fh, mpi_off, readdata, DIMSIZE, MPI_BYTE, + &mpi_stat)) + != MPI_SUCCESS){ + MPI_Error_string(mpi_err, mpi_err_str, &mpi_err_strlen); + PRINTID; + printf("MPI_File_read_at offset(%ld), bytes (%d), failed (%s)\n", + (long) mpi_off, (int) DIMSIZE, mpi_err_str); + return 1; + }; + for (i=0; i < DIMSIZE; i++){ + expect_val = irank*DIMSIZE + i; + if (readdata[i] != expect_val){ + PRINTID; + printf("read data[%d:%d] got %02x, expect %02x\n", irank, i, + readdata[i], expect_val); + nerrors++; + } + } + + MPI_File_close(&fh); + + PRINTID; + if (nerrors > 0){ + printf("%d data errors detected\n", nerrors); + }else{ + printf("all tests passed\n"); + } + + mpi_err = MPI_Barrier(MPI_COMM_WORLD); + return 0; +} + + +/* * parse the command line options */ int @@ -466,6 +616,8 @@ main(int argc, char **argv) goto finish; } + MPI_BANNER("MPIO 1 write Many read test..."); + test_mpio_1wMr(filenames[0], USENONE); MPI_BANNER("MPIO File size range test..."); test_mpio_gb_file(filenames[0]); MPI_BANNER("MPIO independent overlapping writes..."); |