It is not different for active requests; I think it was a mistake to define it the way it is. You can still use MPI_Request_free to free requests that are allocated but not started; which is why I think we should keep it, but change the semantic. From: mpi-22-bounces_at_[hidden] [mailto:mpi-22-bounces_at_[hidden]] On Behalf Of Richard Treumann Sent: Thursday, July 17, 2008 1:57 PM To: MPI 2.2 Subject: Re: [Mpi-22] [Mpi-forum] MPI 2.2 proposal: resolving MPI_Request_free issues How is this different from saying MPI_REQUEST_FREE was a mistake. The behavior of an application that uses this call is undefined. Of course we could add MPI_NO_REQUEST_FREE as an MPI_Init time assertion and say that any MPI implementation optimization that create the problems Erez describes are only valid when the application has asserted MPI_NO_REQUEST_FREE. 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-22-bounces_at_[hidden] wrote on 07/17/2008 03:40:55 PM:

The text specifically would say that writing or freeing the buffer after calling MPI_Request_free is unsafe.

Thanks, .Erez

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