[mpi-22] FW: [mpi-21] Proposal: MPI_OFFSET built-in type

[Richard Graham]

Do you think this should go into 2.2 or 3.0 ?  I ask not because the change
is large, but because it will change the signature of several interface
functions (presumably marking the older functions as deprecated - for
removal in X number of years).  There is another change that I would like to
see added to the standard, which is adding a way to convey information
between MPI_Alloc_mem() to the functions using this memory, w/o forcing the
implementations to try and use all sorts of non-portable solutions to figure
out if this memory can be used "as-is" by the network layer, of if it needs
to be "prepared" (pinned, and ?).

It seems prudent to combine such interface changes into the smallest number
of changes (1 is preferred).

What do you think ?
Rich

On 1/24/08 12:18 PM, "Rajeev Thakur" <thakur_at_[hidden]> wrote:

> A similar one is needed for MPI_Aint.
> 
> Rajeev 
> 
>> -----Original Message-----
>> From: mpi-22-bounces_at_[hidden]
>> [mailto:mpi-22-bounces_at_[hidden]] On Behalf Of Richard Graham
>> Sent: Thursday, January 24, 2008 11:09 AM
>> To: mpi-22_at_[hidden]
>> Subject: [mpi-22] FW: [mpi-21] Proposal: MPI_OFFSET built-in type
>> 
>> Moving this to the appropriate list.
>> 
>> Rich
>> 
>> ------ Forwarded Message
>> From: Robert Latham <robl_at_[hidden]>
>> Reply-To: "Mailing list for discussion of MPI 2.1"
>> <mpi-21_at_[hidden]>
>> Date: Thu, 24 Jan 2008 10:41:52 -0600
>> To: <mpi-21_at_[hidden]>
>> Subject: [mpi-21] Proposal: MPI_OFFSET built-in type
>> 
>> I hope this is less contentious than adding 'const' keywords...
>> 
>> 
>> I would like to propose a new built-in type MPI_OFFSET, defined to be
>> a type corresponding to INTEGER(KIND=MPI_OFFSET_KIND) or MPI_Offset
>> 
>> This is a minor addition to the standard, which would have no impact
>> on existing code while serving to simplify code which exchanges file
>> offsets among processes.
>> 
>> There is a workaround in the standard: a user can define a type from
>> MPI_BYTE:
>> 
>>  MPI_Type_contiguous(sizeof(MPI_Offset), MPI_BYTE, &offtype);
>> 
>> However, it would clearly be more convienient to operate on built-in
>> types.  
>> 
>> MPI Datatype: MPI_OFFSET
>> Corresponding C type: long long int
>> Corresponding Fortran type: INTEGER(KIND=MPI_OFFSET_KIND)
>> 
>> 
>> Thanks
>> ==rob
>> 
>> -- 
>> Rob Latham
>> Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
>> Argonne National Lab, IL USA                 B29D F333 664A 4280 315B
>> _______________________________________________
>> mpi-21 mailing list
>> mpi-21_at_[hidden]
>> http://lists.cs.uiuc.edu/mailman/listinfo/mpi-21
>> 
>> ------ End of Forwarded Message
>> 
>> _______________________________________________
>> mpi-22 mailing list
>> mpi-22_at_[hidden]
>> http://lists.cs.uiuc.edu/mailman/listinfo/mpi-22
>> 
>> 
> 
> _______________________________________________
> mpi-22 mailing list
> mpi-22_at_[hidden]
> http://lists.cs.uiuc.edu/mailman/listinfo/mpi-22