Re: amber-developers: Question regarding use of mexit()

From: Scott Brozell <sbrozell.scripps.edu>
Date: Fri, 7 Dec 2007 18:55:38 -0800 (PST)

Hi,

On Fri, 16 Nov 2007, David A. Case wrote:

> On Fri, Nov 16, 2007, Daniel R. Roe wrote:
> > According to the source code I have (current as of 11-06-2007),
> > mexit(6,0) will call MPI_FINALIZE, while mexit(6,1) will call MPI_ABORT.

A tanget is that mexit needs cleaning up.
See the cvs log for revision 9.3.

> > From what I have read of these procedures in the MPI documentation,
> > MPI_FINALIZE should be called by all processes for normal termination.
> > However, it seems that since MPI_ABORT tries to kill all processes in
> > the given communicator (comm_world in this case), it should only be
> > called by the overall master (worldrank==0); if mutiple threads call
> > MPI_ABORT for the same communicator will this result in some processes
> > hanging because they end up waiting for other processes to try the abort?
> >
> > If this is the case then mexit(6,0) should only be called by
> > worldrank==0, and it should be ensured that mexit(6,1) is executed by
> > all processes. Does this make sense?
>
> Sounds like it should be the reverse(?): any process can call mexit(6,1), but
> everyone should call mexit(6,0). Someone would have to do a code audit to see
> how consistent we are in Amber on doing this.

457 mexit calls in 85 files.
8 with status 0; the ones in these files look dubious, ie,
should these be status 1 ?:
./morsify.f:133: call mexit(6,0)
./multisander.f:441: call mexit (6,0)
./multisander.f:558: call mexit(6,0)

Also meriting investigation are those mexit calls with unusual units:
./multisander.f:848: call mexit(-8,0)
./debug.f:356: call mexit(0,0)

Scott
Received on Sun Dec 09 2007 - 06:07:46 PST
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