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: [email protected] [mailto:[email protected]] 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


[email protected] 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
>