Hi Brian, many thanks for the response
> So what exactly is the problem you are seeing? We (the LAM developers)
> unfortunately can not provide general debugging assistance - there are
> too many users and not nearly enough developers. That being said,
> we're more than willing to answer specific questions you might have
> about MPI and specifically about the LAM implementation.
I completely understand what you are saying here, however I would
point out that for new users there seem to be very few places to go to
receive help when attempting to scale the learning curve of parallel
programming. Although this problem was posted here, suggestions came
originally from a subscriber to the list, it simply raises the issue
of where else is there a central repository of working know how and
experience? experts exchange for example list only 79 mpi related
queries.
Most searches on the internet seem to point to academic style lecture
notes/publications or very high end applications, the nature of which
can often be very specific or just difficult to comprehend for
newcommers to parallel programming. As I'm sure was the case with
everyone subscribed, we all had to learn somewhere and of course by
attemping solutions and having mistakes pointed out usually leads to
far better learning than trying to decipher existing code and tailor
it, so that said, thanks again for pointing out the errors, is there
anywhere else then that I can go so that I don't keep annoying the LAM
developers but may get in touch with people who may point out newbie
(silly) mistakes ??? ; )
Many thanks,
k
> I do see a couple of problems with your code that seem to indicate a
> misunderstanding of the MPI send/recv interfaces. You might want to
> find a good resource on using MPI and work through the examples. One I
> would suggest is the NCSA's Introduction to MPI:
>
> http://webct.ncsa.uiuc.edu:8900/public/MPI/
>
> In particular, in the client you have an MPI_Waitany at the top of a
> while(1) loop, but only post a non-blocking operation outside of the
> while() loop. This might work the first time through the loop, but
> after that, you might not have any requests that can be progressed to
> completion. You also don't call any Test or Wait functions for the
> non-blocking communication used in the master, so the communication may
> never complete there.
>
>
> Hope this helps,
>
> Brian
>
> --
> Brian Barrett
> LAM/MPI developer and all around nice guy
> Have an LAM/MPI day: http://www.lam-mpi.org/
>
>
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