Hi, The only example that works is hello_c.c. All others (that use MPI_Send and MPI_Recv)(connectivity_c.c and ring_c.c) block after the first MPI_Send / MPI_Recv (although the first Send/Receive pair works well for all processes, subsequent Send/Receive pairs block). My slurm version is 2.1.0. It is also worth mentioning that all examples work when not using SLURM (launching with "mpirun -np 5 <exaple_app>"). Blocking occurs only when I try to run on multiple hosts with SLURM ("salloc -N5 mpirun <example_app>").
Adrian ________________________________ From: Jeff Squyres <jsquy...@cisco.com> To: adrian sabou <adrian.sa...@yahoo.com>; Open MPI Users <us...@open-mpi.org> Sent: Wednesday, February 1, 2012 10:32 PM Subject: Re: [OMPI users] OpenMPI / SLURM -> Send/Recv blocking On Jan 31, 2012, at 11:16 AM, adrian sabou wrote: > Like I said, a very simple program. > When launching this application with SLURM (using "salloc -N2 mpirun > ./<my_app>"), it hangs at the barrier. Are you able to run the MPI example programs in examples/ ? > However, it passes the barrier if I launch it without SLURM (using "mpirun > -np 2 ./<my_app>"). I first noticed this problem when my application hanged > if I tried to send two successive messages from a process to another. Only > the first MPI_Send would work. The second MPI_Send would block indefinitely. > I was wondering whether any of you have encountered a similar problem, or may > have an ideea as to what is causing the Send/Receive pair to block when using > SLURM. The exact output in my console is as follows: > > salloc: Granted job allocation 1138 > Process 0 - Sending... > Process 1 - Receiving... > Process 1 - Received. > Process 1 - Barrier reached. > Process 0 - Sent. > Process 0 - Barrier reached. > (it just hangs here) > > I am new to MPI programming and to OpenMPI and would greatly appreciate any > help. My OpenMPI version is 1.4.4 (although I have also tried it on 1.5.4), > my SLURM version is 0.3.3-1 (slurm-llnl 2.1.0-1), I'm not sure what SLURM version that is -- my "srun --version" shows 2.2.4. 0.3.3 would be pretty ancient, no? -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/