[OMPI devel] collective problems

[David Daniel]

Hi Folks,






I see this with

  openmpi-1.2.3 or openmpi-1.2.4
  ofed 1.2
  linux 2.6.19 + patches
  gcc (GCC) 3.4.5 20051201 (Red Hat 3.4.5-2)
  4 socket, dual core opterons

run as

  mpirun --mca btl self,openib --npernode 1 --np 4 bcast-hang



Anyone else seeing similar?  Any ideas for workarounds?

As a point of reference, mvapich2 0.9.8 works fine.

Thanks, David

I have been seeing some nasty behaviour in collectives, particularly bcast and reduce. Attached is a reproducer (for bcast). The code will rapidly slow to a crawl (usually interpreted as a hang in real applications) and sometimes gets killed with sigbus or sigterm. To my now uneducated eye it looks as if the root process is rushing ahead and not progressing earlier bcasts.

bcast-hang.c
Description: Binary data