diff options
Diffstat (limited to 'src/H5FDmpio.c')
| -rw-r--r-- | src/H5FDmpio.c | 38 |
1 files changed, 28 insertions, 10 deletions
diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c index f285f1a..3cf1968 100644 --- a/src/H5FDmpio.c +++ b/src/H5FDmpio.c @@ -934,6 +934,13 @@ done: * * Modifications: * + * John Mainzer -- 9/21/05 + * Modified code to turn off the + * H5FD_FEAT_ACCUMULATE_METADATA_WRITE flag. + * With the movement of + * all cache writes to process 0, this flag has become + * problematic in PHDF5. + * *------------------------------------------------------------------------- */ static herr_t @@ -947,15 +954,6 @@ H5FD_mpio_query(const H5FD_t UNUSED *_file, unsigned long *flags /* out */) if(flags) { *flags=0; *flags|=H5FD_FEAT_AGGREGATE_METADATA; /* OK to aggregate metadata allocations */ - - /* Distinguish between updating the metadata accumulator on writes and - * reads. This is particularly (perhaps only, even) important for MPI-I/O - * where we guarantee that writes are collective, but reads may not be. - * If we were to allow the metadata accumulator to be written during a - * read operation, the application would hang. - */ - *flags|=H5FD_FEAT_ACCUMULATE_METADATA_WRITE; /* OK to accumulate metadata for faster writes */ - *flags|=H5FD_FEAT_AGGREGATE_SMALLDATA; /* OK to aggregate "small" raw data allocations */ } /* end if */ @@ -1553,9 +1551,18 @@ H5FD_mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, if(H5P_get(plist,H5AC_BLOCK_BEFORE_META_WRITE_NAME,&block_before_meta_write)<0) HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get H5AC property") +#if 0 /* JRM */ + /* The metadata cache now only writes from process 0, which makes + * this synchronization incorrect. I'm leaving this code commented + * out instead of deleting it to remind us that we should re-write + * this function so that a metadata write from any other process + * should flag an error. + * -- JRM 9/1/05 + */ if(block_before_meta_write) if (MPI_SUCCESS!= (mpi_code=MPI_Barrier(file->comm))) HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code) +#endif /* JRM */ /* Only one process will do the actual write if all procs in comm write same metadata */ if (file->mpi_rank != H5_PAR_META_WRITE) { @@ -1616,11 +1623,22 @@ H5FD_mpio_write(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, file->eof = HADDR_UNDEF; done: - /* if only one process writes, need to broadcast the ret_value to other processes */ + +#if 0 /* JRM */ + /* Since metadata writes are now done by process 0 only, this broadcast + * is no longer needed. I leave it in and commented out to remind us + * that we need to re-work this function to reflect this reallity. + * + * -- JRM 9/1/05 + */ + /* if only one process writes, need to broadcast the ret_value to + * other processes + */ if (type!=H5FD_MEM_DRAW) { if (MPI_SUCCESS != (mpi_code=MPI_Bcast(&ret_value, sizeof(ret_value), MPI_BYTE, H5_PAR_META_WRITE, file->comm))) HMPI_DONE_ERROR(FAIL, "MPI_Bcast failed", mpi_code) } /* end if */ +#endif /* JRM */ #ifdef H5FDmpio_DEBUG if (H5FD_mpio_Debug[(int)'t']) |