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From: Brian Barrett (bbarrett_at_[hidden])
Date: 2007-03-20 18:30:03


On Mar 20, 2007, at 3:15 PM, Mike Houston wrote:

> If I only do gets/puts, things seem to be working correctly with
> version
> 1.2. However, if I have a posted Irecv on the target node and issue a
> MPI_Get against that target, MPI_Test on the posed IRecv causes a
> segfaults:
>
> Anyone have suggestions? Sadly, I need to have IRecv's posted. I'll
> attempt to find a workaround, but it looks like the posed IRecv is
> getting all the data of the MPI_Get from the other node. It's like
> the
> message tagging is getting ignored. I've never tried posting two
> different IRecv's with different message tags either...

Hi Mike -

I've spent some time this afternoon looking at the problem and have
some ideas on what could be happening. I don't think it's a data
mismatch (the data intended for the IRecv getting delivered to the
Get), but more a problem with the call to MPI_Test perturbing the
progress flow of the one-sided engine. I can see one or two places
where it's possible this could happen, although I'm having trouble
replicating the problem with any test case I can write. Is it
possible for you to share the code causing the problem (or some small
test case)? It would make me feel considerably better if I could
really understand the conditions required to end up in a seg fault
state.

Thanks,

Brian