On 4 May 2010, at 15:27, Jeff Squyres wrote: > One thing to be careful with a run-time check is that you might not want > *all* processes on a box to try to alloc a sysv segment, fork a child, try to > connect, ...etc. With large count boxen, you might run out of sysv shmem > segments if all procs try the test and/or run into OS serialization issues > (someone here at the Forum cited a 96 core box). So you might want to have > local rank 0 (or the orted? ...but that wouldn't work for srun / direct > launch, etc.) do a test and communicate the results to the rest of the local > procs -- maybe in the modex?
I think as as user I'd be quite surprised if my MPI job was spawning sub-processes during MPI_Init(). Ashley. -- Ashley Pittman, Bath, UK. Padb - A parallel job inspection tool for cluster computing http://padb.pittman.org.uk
