I think this proposal is moot unless it is intended as a loophole to allow an implementation to provide a zero-functionality version of the INFO bindings. The "filename" hint is always present on an MPI_File so there should never be a empty MPI_FILE_GET_INFO return. Dick hh Dick Treumann - MPI Team/TCEM IBM Systems & Technology Group Dept 0lva / MS P963 -- 2455 South Road -- Poughkeepsie, NY 12601 Tele (845) 433-7846 Fax (845) 433-8363 mpi-21-bounces_at_[hidden] wrote on 01/31/2008 08:01:20 AM:

This is a proposal for MPI 2.1, Ballot 4.

I'm asking especially the implementors to check, whether this interpretation is implemented in their MPI implementations, or does not contradict to the existing implementation.

This is a follow up to: MPI_File_get_info in http://www.cs.uiuc.edu/homes/wgropp/projects/parallel/MPI/mpi- errata/index.html with mail discussion not yet existing ___________________________________

Proposal: MPI-2.0 Sect. 9.2.8, File Info, page 219, lines 11-13 read:

MPI_FILE_GET_INFO returns a new info object containing the hints of the file associated with fh. The current setting of all hints actually used by the system related to this open file is returned in info_used. The user is responsible for freeing info_used via MPI_INFO_FREE.

but should read (" or an abort(errorcode)" removed):

MPI_FILE_GET_INFO returns a new info object containing the hints of the file associated with fh. The current setting of all hints actually used by the system related to this open file is returned in info_used. If there does not exist such a hint, MPI_INFO_NULL is returned. The user is responsible for freeing info_used via MPI_INFO_FREE if info_used is not MPI_INFO_NULL. ___________________________________ Rationale for this clarification: This text was missing. It was not clear, whether a MPI_Info handle would be returned that would return nkeys=0 from MPI_INFO_GET_NKEYS. From user's point of view, this behavior might have been expected without this clarification. ___________________________________

As far as I understand, ROMIO is using for all filesystems some default hints and therefore "no-hints" is never returned. MPI_File_set_view and MPI_File_set_info are only modifying values but do not remove keys. Therefore, the info handle cannot become empty.

Best regards Rolf

Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner_at_[hidden] High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530 University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832 Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner Nobelstr. 19, D-70550 Stuttgart, Germany . (Office: Allmandring 30) _______________________________________________ mpi-21 mailing list mpi-21_at_[hidden] http://lists.cs.uiuc.edu/mailman/listinfo/mpi-21

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