Dear all, A) Typo: My colleague Martin Bernreuther detected the following typo: MPI-3.1 Section "3.7.3 Communication Completion", "MPI_WAIT" page 53, lines 24-25 read "[...]. Any other type of request is and the request handle is set to MPI_REQUEST_NULL. [...]" but should read "[...]. Any other type of request is deallocated and the request handle is set to MPI_REQUEST_NULL. [...]" In other Locations, this sentence is correct, i.e., includes the word "deallocated", see MPI-3.1 - page 54, lines 20-21 in MPI_TEST, - page 57, lines 45-46 in MPI_WAITANY, - page 58, lines 35-36 in MPI_TESTANY, - page 59, lines 23-24 in MPI_WAITALL, - page 60, lines 25-26 in MPI_TESTALL, - page 61, lines 19-20 in MPI_WAITSOME, whereas MPI_TESTALL does not contain this sentence due to a shorter description. B) Mal-correction: The correction from MPI-2.2 to MPI-3.0 contains wrong wording for MPI_Wait/Test... in the case of inactive request handles. The correction was done to include also nonblocking collectives and IO. But the change to MPI-3.0 was not correct for inactive persistent request handles. MPI-1.1 - MPI-2.2 used the wording: "A call to MPI WAIT returns when the operation identified by request is complete. If the communication object associated with this request was created by a nonblocking send or receive call, then the object is deallocated by the call to MPI WAIT and the request handle is set to MPI REQUEST NULL. MPI WAIT is a non-local operation. The call returns, in status, [...]. One is allowed to call MPI WAIT with a null or inactive request argument. In this case the operation returns immediately with empty status." For inactive persistent request handles, the text says: - no change for the request handle, - empty status returned. MPI-3.0 and MPI-3.1 uses the following modified wording: "A call to MPI_WAIT returns when the operation identified by request is complete. If the request is an active persistent request, it is marked inactive. Any other type of request is [deallocated] and the request handle is set to MPI_REQUEST_NULL. MPI_WAIT is a non-local operation. The call returns, in status, [...]. One is allowed to call MPI_WAIT with a null or inactive request argument. In this case the operation returns immediately with empty status." For inactive persistent request handles, the text says: - that it shpould be set to MPI_REQUEST_NULL, and - empty status returned. The MPI_REQUEST_NULL was never intented and I expect that no MPI-library has implemented that wrong behavior. Note that in the case of an array of request handles, in a sequence of MPI_Wait/Test-any/some calls, it is allowed to keep the whole array untouched until all regular requests are set to MPI_REQUEST_NULL and all active persistent requests are changed to inactive. Proposal for correcting thos bug: Change all sentences "Any other type of request is deallocated and the request handle is set to MPI_REQUEST_NULL." into "Any other type of non-persistent request is deallocated and the request handle is set to MPI_REQUEST_NULL." The locations are: - page 53, lines 24-25 in MPI_WAIT (together with the typo, see (A) above) - page 54, lines 20-21 in MPI_TEST, - page 57, lines 45-46 in MPI_WAITANY, - page 58, lines 35-36 in MPI_TESTANY, - page 59, lines 23-24 in MPI_WAITALL, - page 60, lines 25-26 in MPI_TESTALL, - page 61, lines 19-20 in MPI_WAITSOME. Best regards Rolf -- Dr. Rolf Rabenseifner . . . . . . . . . .. email [email protected] . 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: Room 1.307) .