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-rw-r--r--src/H5Dmpio.c115
1 files changed, 90 insertions, 25 deletions
diff --git a/src/H5Dmpio.c b/src/H5Dmpio.c
index 2c06800..f5da33d 100644
--- a/src/H5Dmpio.c
+++ b/src/H5Dmpio.c
@@ -37,7 +37,6 @@
#include "H5Eprivate.h" /* Error handling */
#include "H5Fprivate.h" /* File access */
#include "H5FDprivate.h" /* File drivers */
-#include "H5FDmpi.h" /* MPI-based file drivers */
#include "H5Iprivate.h" /* IDs */
#include "H5MMprivate.h" /* Memory management */
#include "H5Oprivate.h" /* Object headers */
@@ -89,10 +88,20 @@
/******************/
/* Combine chunk address and chunk info into a struct for better performance. */
typedef struct H5D_chunk_addr_info_t {
- haddr_t chunk_addr;
- H5D_chunk_info_t chunk_info;
+ haddr_t chunk_addr;
+ H5D_chunk_info_t chunk_info;
} H5D_chunk_addr_info_t;
+/* Rank 0 Bcast values */
+typedef enum H5D_mpio_no_rank0_bcast_cause_t {
+ H5D_MPIO_RANK0_BCAST = 0x00,
+ H5D_MPIO_RANK0_NOT_H5S_ALL = 0x01,
+ H5D_MPIO_RANK0_NOT_CONTIGUOUS = 0x02,
+ H5D_MPIO_RANK0_NOT_FIXED_SIZE = 0x04,
+ H5D_MPIO_RANK0_GREATER_THAN_2GB = 0x08
+} H5D_mpio_no_rank0_bcast_cause_t;
+
+
/*
* Information about a single chunk when performing collective filtered I/O. All
* of the fields of one of these structs are initialized at the start of collective
@@ -281,8 +290,10 @@ H5D__mpio_opt_possible(const H5D_io_info_t *io_info, const H5S_t *file_space,
const H5S_t *mem_space, const H5D_type_info_t *type_info)
{
H5FD_mpio_xfer_t io_xfer_mode; /* MPI I/O transfer mode */
- unsigned local_cause = 0; /* Local reason(s) for breaking collective mode */
- unsigned global_cause = 0; /* Global reason(s) for breaking collective mode */
+ unsigned local_cause[2] = {0,0}; /* [0] Local reason(s) for breaking collective mode */
+ /* [1] Flag if dataset is both: H5S_ALL and small */
+ unsigned global_cause[2] = {0,0}; /* Global reason(s) for breaking collective mode */
+ htri_t is_vl_storage; /* Whether the dataset's datatype is stored in a variable-length form */
htri_t ret_value = SUCCEED; /* Return value */
FUNC_ENTER_PACKAGE
@@ -296,36 +307,37 @@ H5D__mpio_opt_possible(const H5D_io_info_t *io_info, const H5S_t *file_space,
/* For independent I/O, get out quickly and don't try to form consensus */
if(H5CX_get_io_xfer_mode(&io_xfer_mode) < 0)
- HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get MPI-I/O transfer mode")
+ /* Set error flag, but keep going */
+ local_cause[0] |= H5D_MPIO_ERROR_WHILE_CHECKING_COLLECTIVE_POSSIBLE;
if(io_xfer_mode == H5FD_MPIO_INDEPENDENT)
- local_cause |= H5D_MPIO_SET_INDEPENDENT;
+ local_cause[0] |= H5D_MPIO_SET_INDEPENDENT;
/* Optimized MPI types flag must be set */
/* (based on 'HDF5_MPI_OPT_TYPES' environment variable) */
if(!H5FD_mpi_opt_types_g)
- local_cause |= H5D_MPIO_MPI_OPT_TYPES_ENV_VAR_DISABLED;
+ local_cause[0] |= H5D_MPIO_MPI_OPT_TYPES_ENV_VAR_DISABLED;
/* Don't allow collective operations if datatype conversions need to happen */
if(!type_info->is_conv_noop)
- local_cause |= H5D_MPIO_DATATYPE_CONVERSION;
+ local_cause[0] |= H5D_MPIO_DATATYPE_CONVERSION;
/* Don't allow collective operations if data transform operations should occur */
if(!type_info->is_xform_noop)
- local_cause |= H5D_MPIO_DATA_TRANSFORMS;
+ local_cause[0] |= H5D_MPIO_DATA_TRANSFORMS;
/* Check whether these are both simple or scalar dataspaces */
if(!((H5S_SIMPLE == H5S_GET_EXTENT_TYPE(mem_space) || H5S_SCALAR == H5S_GET_EXTENT_TYPE(mem_space))
&& (H5S_SIMPLE == H5S_GET_EXTENT_TYPE(file_space) || H5S_SCALAR == H5S_GET_EXTENT_TYPE(file_space))))
- local_cause |= H5D_MPIO_NOT_SIMPLE_OR_SCALAR_DATASPACES;
+ local_cause[0] |= H5D_MPIO_NOT_SIMPLE_OR_SCALAR_DATASPACES;
/* Dataset storage must be contiguous or chunked */
if(!(io_info->dset->shared->layout.type == H5D_CONTIGUOUS ||
io_info->dset->shared->layout.type == H5D_CHUNKED))
- local_cause |= H5D_MPIO_NOT_CONTIGUOUS_OR_CHUNKED_DATASET;
+ local_cause[0] |= H5D_MPIO_NOT_CONTIGUOUS_OR_CHUNKED_DATASET;
/* check if external-file storage is used */
if(io_info->dset->shared->dcpl_cache.efl.nused > 0)
- local_cause |= H5D_MPIO_NOT_CONTIGUOUS_OR_CHUNKED_DATASET;
+ local_cause[0] |= H5D_MPIO_NOT_CONTIGUOUS_OR_CHUNKED_DATASET;
/* The handling of memory space is different for chunking and contiguous
* storage. For contiguous storage, mem_space and file_space won't change
@@ -340,31 +352,84 @@ H5D__mpio_opt_possible(const H5D_io_info_t *io_info, const H5S_t *file_space,
* is less than 3. The functions needed (MPI_Mprobe and MPI_Imrecv) will
* not be available.
*/
- if (io_info->op_type == H5D_IO_OP_WRITE &&
- io_info->dset->shared->layout.type == H5D_CHUNKED &&
- io_info->dset->shared->dcpl_cache.pline.nused > 0)
- local_cause |= H5D_MPIO_PARALLEL_FILTERED_WRITES_DISABLED;
+ if(io_info->op_type == H5D_IO_OP_WRITE &&
+ io_info->dset->shared->layout.type == H5D_CHUNKED &&
+ io_info->dset->shared->dcpl_cache.pline.nused > 0)
+ local_cause[0] |= H5D_MPIO_PARALLEL_FILTERED_WRITES_DISABLED;
#endif
+ /* Check if we are able to do a MPI_Bcast of the data from one rank
+ * instead of having all the processes involved in the collective I/O call.
+ */
+
+ /* Check to see if the process is reading the entire dataset */
+ if(H5S_GET_SELECT_TYPE(file_space) != H5S_SEL_ALL)
+ local_cause[1] |= H5D_MPIO_RANK0_NOT_H5S_ALL;
+ /* Only perform this optimization for contigous datasets, currently */
+ else if(H5D_CONTIGUOUS != io_info->dset->shared->layout.type)
+ /* Flag to do a MPI_Bcast of the data from one proc instead of
+ * having all the processes involved in the collective I/O.
+ */
+ local_cause[1] |= H5D_MPIO_RANK0_NOT_CONTIGUOUS;
+ else if((is_vl_storage = H5T_is_vl_storage(type_info->dset_type)) < 0)
+ local_cause[0] |= H5D_MPIO_ERROR_WHILE_CHECKING_COLLECTIVE_POSSIBLE;
+ else if(is_vl_storage)
+ local_cause[1] |= H5D_MPIO_RANK0_NOT_FIXED_SIZE;
+ else {
+ size_t type_size; /* Size of dataset's datatype */
+
+ /* Retrieve the size of the dataset's datatype */
+ if(0 == (type_size = H5T_GET_SIZE(type_info->dset_type)))
+ local_cause[0] |= H5D_MPIO_ERROR_WHILE_CHECKING_COLLECTIVE_POSSIBLE;
+ else {
+ hssize_t snelmts; /* [Signed] # of elements in dataset's dataspace */
+
+ /* Retrieve the size of the dataset's datatype */
+ if((snelmts = H5S_GET_EXTENT_NPOINTS(file_space)) < 0)
+ local_cause[0] |= H5D_MPIO_ERROR_WHILE_CHECKING_COLLECTIVE_POSSIBLE;
+ else {
+ hsize_t dset_size;
+
+ /* Determine dataset size */
+ dset_size = ((hsize_t)snelmts) * type_size;
+
+ /* If the size of the dataset is less than 2GB then do an MPI_Bcast
+ * of the data from one process instead of having all the processes
+ * involved in the collective I/O.
+ */
+ if(dset_size > ((hsize_t)(2.0F * H5_GB) - 1))
+ local_cause[1] |= H5D_MPIO_RANK0_GREATER_THAN_2GB;
+ } /* end else */
+ } /* end else */
+ } /* end else */
+
/* Check for independent I/O */
- if(local_cause & H5D_MPIO_SET_INDEPENDENT)
- global_cause = local_cause;
+ if(local_cause[0] & H5D_MPIO_SET_INDEPENDENT)
+ global_cause[0] = local_cause[0];
else {
int mpi_code; /* MPI error code */
/* Form consensus opinion among all processes about whether to perform
* collective I/O
*/
- if(MPI_SUCCESS != (mpi_code = MPI_Allreduce(&local_cause, &global_cause, 1, MPI_UNSIGNED, MPI_BOR, io_info->comm)))
+ if(MPI_SUCCESS != (mpi_code = MPI_Allreduce(&local_cause, &global_cause, 2, MPI_UNSIGNED, MPI_BOR, io_info->comm)))
HMPI_GOTO_ERROR(FAIL, "MPI_Allreduce failed", mpi_code)
} /* end else */
/* Set the local & global values of no-collective-cause in the API context */
- H5CX_set_mpio_local_no_coll_cause(local_cause);
- H5CX_set_mpio_global_no_coll_cause(global_cause);
+ H5CX_set_mpio_local_no_coll_cause(local_cause[0]);
+ H5CX_set_mpio_global_no_coll_cause(global_cause[0]);
+
+ /* Set read-with-rank0-and-bcast flag if possible */
+ if(global_cause[0] == 0 && global_cause[1] == 0) {
+ H5CX_set_mpio_rank0_bcast(TRUE);
+#ifdef H5_HAVE_INSTRUMENTED_LIBRARY
+ H5CX_test_set_mpio_coll_rank0_bcast(TRUE);
+#endif /* H5_HAVE_INSTRUMENTED_LIBRARY */
+ } /* end if */
/* Set the return value, based on the global cause */
- ret_value = global_cause > 0 ? FALSE : TRUE;
+ ret_value = global_cause[0] > 0 ? FALSE : TRUE;
done:
FUNC_LEAVE_NOAPI(ret_value)
@@ -3069,8 +3134,8 @@ H5D__filtered_collective_chunk_entry_io(H5D_filtered_collective_io_info_t *chunk
chunk_entry->chunk_states.new_chunk.length = chunk_entry->chunk_states.chunk_current.length;
/* Currently, these chunk reads are done independently and will likely
- * cause issues with collective metadata reads enabled. In the future,
- * this should be refactored to use collective chunk reads - JTH */
+ * cause issues with collective metadata reads enabled. In the future,
+ * this should be refactored to use collective chunk reads - JTH */
/* Get the original state of parallel I/O transfer mode */
if(H5CX_get_io_xfer_mode(&xfer_mode) < 0)