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Subject: Re: [OMPI users] Program deadlocks, on simple send/recv loop
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2009-12-01 19:50:05


(for the web archives)

Brock and I talked about this .f90 code a bit off list -- he's going
to investigate with the test author a bit more because both of us are
a bit confused by the F90 array syntax used.

On Dec 1, 2009, at 10:46 AM, Brock Palen wrote:

> The attached code, is an example where openmpi/1.3.2 will lock up, if
> ran on 48 cores, of IB (4 cores per node),
> The code loops over recv from all processors on rank 0 and sends from
> all other ranks, as far as I know this should work, and I can't see
> why not.
> Note yes I know we can do the same thing with a gather, this is a
> simple case to demonstrate the issue.
> Note that if I increase the openib eager limit, the program runs,
> which normally means improper MPI, but I can't on my own figure out
> the problem with this code.
>
> Any input on why code like this locks up, unless we up the eager
> buffer would be helpful, as we should be be having to up the buffer
> size, just to make code run, makes me feel hacky and dirty.
>
>
> <sendbuf.f90><ATT9198877.txt><ATT9198879.txt>

-- 
Jeff Squyres
jsquyres_at_[hidden]