diff options
Diffstat (limited to 'src/H5FDmpio.c')
| -rw-r--r-- | src/H5FDmpio.c | 89 |
1 files changed, 60 insertions, 29 deletions
diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c index 87f8b6a..689f43c 100644 --- a/src/H5FDmpio.c +++ b/src/H5FDmpio.c @@ -1414,31 +1414,32 @@ static herr_t H5FD_mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, hid_t H5_ATTR_UNUSED dxpl_id, haddr_t addr, size_t size, void *buf/*out*/) { - H5FD_mpio_t *file = (H5FD_mpio_t*)_file; - MPI_Offset mpi_off; - MPI_Status mpi_stat; /* Status from I/O operation */ - int mpi_code; /* mpi return code */ - MPI_Datatype buf_type = MPI_BYTE; /* MPI description of the selection in memory */ - int size_i; /* Integer copy of 'size' to read */ + H5FD_mpio_t *file = (H5FD_mpio_t*)_file; + MPI_Offset mpi_off; + MPI_Status mpi_stat; /* Status from I/O operation */ + int mpi_code; /* mpi return code */ + MPI_Datatype buf_type = MPI_BYTE; /* MPI description of the selection in memory */ + int size_i; /* Integer copy of 'size' to read */ #if MPI_VERSION >= 3 - MPI_Count bytes_read; /* Number of bytes read in */ + MPI_Count bytes_read = 0; /* Number of bytes read in */ MPI_Count type_size; /* MPI datatype used for I/O's size */ MPI_Count io_size; /* Actual number of bytes requested */ MPI_Count n; #else - int bytes_read; /* Number of bytes read in */ + int bytes_read = 0; /* Number of bytes read in */ int type_size; /* MPI datatype used for I/O's size */ int io_size; /* Actual number of bytes requested */ - int n; + int n; #endif - hbool_t use_view_this_time = FALSE; - herr_t ret_value = SUCCEED; + hbool_t use_view_this_time = FALSE; + hbool_t rank0_bcast = FALSE; /* If read-with-rank0-and-bcast flag was used */ + herr_t ret_value = SUCCEED; FUNC_ENTER_NOAPI_NOINIT #ifdef H5FDmpio_DEBUG if (H5FD_mpio_Debug[(int)'t']) - fprintf(stdout, "Entering H5FD_mpio_read\n" ); + fprintf(stdout, "Entering H5FD_mpio_read\n" ); #endif HDassert(file); HDassert(H5FD_MPIO==file->pub.driver_id); @@ -1457,12 +1458,12 @@ H5FD_mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, #ifdef H5FDmpio_DEBUG if (H5FD_mpio_Debug[(int)'r']) fprintf(stdout, "in H5FD_mpio_read mpi_off=%ld size_i=%d\n", - (long)mpi_off, size_i ); + (long)mpi_off, size_i ); #endif /* Only look for MPI views for raw data transfers */ if(type == H5FD_MEM_DRAW) { - H5FD_mpio_xfer_t xfer_mode; /* I/O transfer mode */ + H5FD_mpio_xfer_t xfer_mode; /* I/O transfer mode */ /* Get the transfer mode from the API context */ if(H5CX_get_io_xfer_mode(&xfer_mode) < 0) @@ -1475,7 +1476,7 @@ H5FD_mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, * could mean "use MPI_BYTE" by convention). */ if(xfer_mode==H5FD_MPIO_COLLECTIVE) { - MPI_Datatype file_type; + MPI_Datatype file_type; /* Remember that views are used */ use_view_this_time = TRUE; @@ -1502,8 +1503,8 @@ H5FD_mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, H5FD_mpio_collective_opt_t coll_opt_mode; #ifdef H5FDmpio_DEBUG - if (H5FD_mpio_Debug[(int)'t']) - fprintf(stdout, "H5FD_mpio_read: using MPIO collective mode\n"); + if (H5FD_mpio_Debug[(int)'t']) + fprintf(stdout, "H5FD_mpio_read: using MPIO collective mode\n"); #endif /* Get the collective_opt property to check whether the application wants to do IO individually. */ if(H5CX_get_mpio_coll_opt(&coll_opt_mode) < 0) @@ -1514,8 +1515,25 @@ H5FD_mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, if(H5FD_mpio_Debug[(int)'t']) fprintf(stdout, "H5FD_mpio_read: doing MPI collective IO\n"); #endif - if(MPI_SUCCESS != (mpi_code = MPI_File_read_at_all(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat))) - HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at_all failed", mpi_code) + /* Check whether we should read from rank 0 and broadcast to other ranks */ + if(H5CX_get_mpio_rank0_bcast()) { +#ifdef H5FDmpio_DEBUG + if(H5FD_mpio_Debug[(int)'r']) + HDfprintf(stdout, "%s: doing read-rank0-and-MPI_Bcast\n", FUNC); +#endif + /* Indicate path we've taken */ + rank0_bcast = TRUE; + + /* Read on rank 0 Bcast to other ranks */ + if(file->mpi_rank == 0) + if(MPI_SUCCESS != (mpi_code = MPI_File_read_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat))) + HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at failed", mpi_code) + if(MPI_SUCCESS != (mpi_code = MPI_Bcast(buf, size_i, buf_type, 0, file->comm))) + HMPI_GOTO_ERROR(FAIL, "MPI_Bcast failed", mpi_code) + } /* end if */ + else + if(MPI_SUCCESS != (mpi_code = MPI_File_read_at_all(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat))) + HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at_all failed", mpi_code) } /* end if */ else { #ifdef H5FDmpio_DEBUG @@ -1534,24 +1552,37 @@ H5FD_mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, HMPI_GOTO_ERROR(FAIL, "MPI_File_set_view failed", mpi_code) } else { if(MPI_SUCCESS != (mpi_code = MPI_File_read_at(file->f, mpi_off, buf, size_i, buf_type, &mpi_stat))) - HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at failed", mpi_code) + HMPI_GOTO_ERROR(FAIL, "MPI_File_read_at failed", mpi_code) } - /* How many bytes were actually read? */ + /* Only retrieve bytes read if this rank _actually_ participated in I/O */ + if(!rank0_bcast || (rank0_bcast && file->mpi_rank == 0) ) { + /* How many bytes were actually read? */ #if MPI_VERSION >= 3 - if (MPI_SUCCESS != (mpi_code = MPI_Get_elements_x(&mpi_stat, buf_type, &bytes_read))) + if(MPI_SUCCESS != (mpi_code = MPI_Get_elements_x(&mpi_stat, buf_type, &bytes_read))) #else - if (MPI_SUCCESS != (mpi_code = MPI_Get_elements(&mpi_stat, MPI_BYTE, &bytes_read))) + if(MPI_SUCCESS != (mpi_code = MPI_Get_elements(&mpi_stat, MPI_BYTE, &bytes_read))) #endif - HMPI_GOTO_ERROR(FAIL, "MPI_Get_elements failed", mpi_code) + HMPI_GOTO_ERROR(FAIL, "MPI_Get_elements failed", mpi_code) + } /* end if */ + + /* If the rank0-bcast feature was used, broadcast the # of bytes read to + * other ranks, which didn't perform any I/O. + */ + /* NOTE: This could be optimized further to be combined with the broadcast + * of the data. (QAK - 2019/1/2) + */ + if(rank0_bcast) + if(MPI_SUCCESS != MPI_Bcast(&bytes_read, 1, MPI_LONG_LONG, 0, file->comm)) + HMPI_GOTO_ERROR(FAIL, "MPI_Bcast failed", 0) /* Get the type's size */ #if MPI_VERSION >= 3 - if (MPI_SUCCESS != (mpi_code = MPI_Type_size_x(buf_type, &type_size))) + if(MPI_SUCCESS != (mpi_code = MPI_Type_size_x(buf_type, &type_size))) #else - if (MPI_SUCCESS != (mpi_code = MPI_Type_size(buf_type, &type_size))) + if(MPI_SUCCESS != (mpi_code = MPI_Type_size(buf_type, &type_size))) #endif - HMPI_GOTO_ERROR(FAIL, "MPI_Type_size failed", mpi_code) + HMPI_GOTO_ERROR(FAIL, "MPI_Type_size failed", mpi_code) /* Compute the actual number of bytes requested */ io_size=type_size*size_i; @@ -1564,12 +1595,12 @@ H5FD_mpio_read(H5FD_t *_file, H5FD_mem_t H5_ATTR_UNUSED type, * This gives us zeroes beyond end of physical MPI file. */ if ((n=(io_size-bytes_read)) > 0) - HDmemset((char*)buf+bytes_read, 0, (size_t)n); + HDmemset((char*)buf+bytes_read, 0, (size_t)n); done: #ifdef H5FDmpio_DEBUG if (H5FD_mpio_Debug[(int)'t']) - fprintf(stdout, "Leaving H5FD_mpio_read\n" ); + fprintf(stdout, "Leaving H5FD_mpio_read\n" ); #endif FUNC_LEAVE_NOAPI(ret_value) |