On Apr 6, 2009, at 6:22 PM, Steve Lowder wrote:
When I run the MPI version and set --mca opal_signal 6,7,11 the code
doesn't abort on underflow. I'd like to know if I'm interpreting this
behavior correctly, it appears that the mpi versus no mpi cases handle
underflow differently. I'm assuming OpenMPI has a handler that
processes
the interrupts ahead of the Fortran RTL, stopping execution.
Otherwise
the Fortran RTL handler would just ignore the underflow. Do I sort of
understand what is going on here? Is there another solution short of
the --mca opal_signal switch?
You are correct; Open MPI inserts an FPE handler unless you tell it
to; your case is fairly special in that you *don't* want to see a
signal/stack trace when an FPE occurs. My $0.02 is that it is
probably easiest to always run with the opal_signal MCA param value
set to exclude the FPE handler, as you discovered.
--
Jeff Squyres
Cisco Systems
