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Subject: Re: [OMPI users] Accessing to the send buffer
From: Richard Treumann (treumann_at_[hidden])
Date: 2010-08-02 12:21:51


For reading the data from an isend buffer to cause problems, the
underlying hardware would need to have very unusual characteristic that
the MPI implementation is exploiting. People have imagined hardware
characteristics that could make reading an Isend buffer a problem but I
have never heard of real hardware where it would be. (Imagine hardware
where posting an ISEND causes addressability of the underlying memory to
be handed over to an adapter until the send is done. The processor loses
addressability. No such real hardware I ever heard of but if there were,
the send buffer access rule would be relevant)

The Forum has decided the send buffer rule is to restrictive.

Dick Treumann - MPI Team
IBM Systems & Technology Group
Dept X2ZA / MS P963 -- 2455 South Road -- Poughkeepsie, NY 12601
Tele (845) 433-7846 Fax (845) 433-8363