diff options
Diffstat (limited to 'src/H5Dmpio.c')
| -rw-r--r-- | src/H5Dmpio.c | 63 |
1 files changed, 33 insertions, 30 deletions
diff --git a/src/H5Dmpio.c b/src/H5Dmpio.c index 8c78af2..f2f3efa 100644 --- a/src/H5Dmpio.c +++ b/src/H5Dmpio.c @@ -172,10 +172,43 @@ H5D_mpio_opt_possible(const H5D_io_info_t *io_info, const H5S_t *file_space, HDassert(file_space); HDassert(type_info); + /* Global decisions. These conditions are common to all processes and they + * will all arrive at the same conclusions, without requiring communication. + */ + /* For independent I/O, get out quickly and don't try to form consensus */ if(io_info->dxpl_cache->xfer_mode == H5FD_MPIO_INDEPENDENT) HGOTO_DONE(FALSE); + /* Optimized MPI types flag must be set and it must be collective IO */ + /* (Don't allow parallel I/O for the MPI-posix driver, since it doesn't do real collective I/O) */ + /* (Global decision if all processes share the same environment, which is reasonable) */ + if(!(H5S_mpi_opt_types_g && io_info->dxpl_cache->xfer_mode == H5FD_MPIO_COLLECTIVE + && !IS_H5FD_MPIPOSIX(io_info->dset->oloc.file))) + HGOTO_DONE(FALSE); + + /* Dataset storage must be contiguous or chunked */ + if(!(io_info->dset->shared->layout.type == H5D_CONTIGUOUS || + io_info->dset->shared->layout.type == H5D_CHUNKED)) + HGOTO_DONE(FALSE); + + /* The handling of memory space is different for chunking and contiguous + * storage. For contiguous storage, mem_space and file_space won't change + * when it it is doing disk IO. For chunking storage, mem_space will + * change for different chunks. So for chunking storage, whether we can + * use collective IO will defer until each chunk IO is reached. + */ + + /* Don't allow collective operations if filters need to be applied */ + if(io_info->dset->shared->layout.type == H5D_CHUNKED && + io_info->dset->shared->dcpl_cache.pline.nused > 0) + HGOTO_DONE(FALSE); + + + /* Local decisions. These conditions could be different on each process, + * and require communication to verify. + */ + /* Don't allow collective operations if datatype conversions need to happen */ if(!type_info->is_conv_noop) { local_opinion = FALSE; @@ -188,14 +221,6 @@ H5D_mpio_opt_possible(const H5D_io_info_t *io_info, const H5S_t *file_space, goto broadcast; } /* end if */ - /* Optimized MPI types flag must be set and it must be collective IO */ - /* (Don't allow parallel I/O for the MPI-posix driver, since it doesn't do real collective I/O) */ - if(!(H5S_mpi_opt_types_g && io_info->dxpl_cache->xfer_mode == H5FD_MPIO_COLLECTIVE - && !IS_H5FD_MPIPOSIX(io_info->dset->oloc.file))) { - local_opinion = FALSE; - goto broadcast; - } /* end if */ - /* 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)))) { @@ -210,28 +235,6 @@ H5D_mpio_opt_possible(const H5D_io_info_t *io_info, const H5S_t *file_space, goto broadcast; } /* end if */ - /* 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_opinion = FALSE; - goto broadcast; - } /* end if */ - - /* The handling of memory space is different for chunking and contiguous - * storage. For contiguous storage, mem_space and file_space won't change - * when it it is doing disk IO. For chunking storage, mem_space will - * change for different chunks. So for chunking storage, whether we can - * use collective IO will defer until each chunk IO is reached. - */ - - /* Don't allow collective operations if filters need to be applied */ - if(io_info->dset->shared->layout.type == H5D_CHUNKED) { - if(io_info->dset->shared->dcpl_cache.pline.nused > 0) { - local_opinion = FALSE; - goto broadcast; - } /* end if */ - } /* end if */ - broadcast: /* Form consensus opinion among all processes about whether to perform * collective I/O |