[gmx-developers] Configure warning for MPI version, was: [gmx-users] New beta release: 4.5-beta3

[Bogdan Costescu]

On Wed, Aug 11, 2010 at 11:58 PM, Roland Schulz <roland at utk.edu> wrote:
> OpenMPI 1.4.0 hangs on GCC 4.4.x on x86/x64

Was this by any chance run on a Nehalem CPU using shared memory ? (not
necessarily sm alone). This particular combination (gcc >= 4.4,
Nehalem, sm) has been known to cause problems which are supposed to be
fixed in OpenMPI 1.4.2. However this problem doesn't manifest itself
on the same computers with older gcc, when not using sm or on
computers with other CPUs. So I think that banning OpenMPI 1.4.0
outright is a too tough measure.

If you still have access to this combination, could you try running
with 'mpirun -mca btl ^sm ...' ? This should disable sm and allow
other mechanisms to be used for on-node communication (openib or tcp
most likely).

Cheers,
Bogdan