On Oct 31, 2007, at 11:47 AM, Karsten Bolding wrote:
Does OpenMPI detect if procceses share memory and hence do not
communicate via sockets.
Yes.
But if you lie to Open MPI and tell it that there are more processors
than there really are, we may not recognize that the machine is
oversubscrib
On Wed, Oct 31, 2007 at 11:13:46 -0700, Jeff Squyres wrote:
> On Oct 31, 2007, at 10:45 AM, Karsten Bolding wrote:
>
> > In a different thread I read about a performance penalty in OpenMPI if
> > more than one MPI-process is running on one processor/core - is that
> > correct? I mean having max-sl
On Oct 31, 2007, at 10:45 AM, Karsten Bolding wrote:
In a different thread I read about a performance penalty in OpenMPI if
more than one MPI-process is running on one processor/core - is that
correct? I mean having max-slots>4 on a quad-core machine.
Open MPI polls for message passing progres
On Wed, Oct 31, 2007 at 09:27:48 -0700, Jeff Squyres wrote:
> I think you should use the MPI_PROC_NULL constant itself, not a hard-
> coded value of -1.
the value -1 was in the neighbor specification file.
>
> Specifically: the value of MPI_PROC_NULL is not set in the MPI
> standard -- so imp
I think you should use the MPI_PROC_NULL constant itself, not a hard-
coded value of -1.
Specifically: the value of MPI_PROC_NULL is not set in the MPI
standard -- so implementations are free to choose whatever value they
want. In Open MPI, MPI_PROC_NULL is -2. So using -1 is an illegal
