[mvapich-discuss] mpi_ssend and system call (fortran) conflict

[Matthew Koop]

Hi Noam,

By default we do not turn on the fork-safe support since there is some
slight performance overhead. To enable the support you need to use the
IBV_FORK_SAFE=1 enviroment variable

e.g.
  mpirun_rsh -np X -hostfile Y IBV_FORK_SAFE=1 ./exec

This is in 7.1.2 of the MVAPICH user guide as well.

Let us know if this helps or not. Thanks!

Matt




On Fri, 18 Jul 2008, Noam Bernstein wrote:

> I've been seeing a problem with mvapich with Intel ifort (10.1.015),
> where a call to system
> will cause subsequent calls to mpi_ssend to hang or crash.  Using
> mpi_send seems to be
> fine, and removing the call to system also fixes the problem.
>
> This is on a dual Opteron, Infiniband system (Mellanox HCAs), with
> OFED 1.2.5.1.  There
> A relaxed error (related to fork) was supposedly fixed in this
> version of  OFED (1.2.1 according
> to the release notes http://www.open-mpi.org/svn/new.php).
>
> mvapich-1.0.1 with make.mvapich.gen2 hangs
>
> mvapich2-1.0.3 with make.mvapich2.ofa crashes, with the message:
>
>    send desc error
>    [0] Abort: [] Got completion with error 1, vendor code=69, dest
> rank=1
>     at line 519 in file ibv_channel_manager.c
>
> (rank 0 is the sender).
>
> I'm starting with this list, since the fact that mpi_ssend has
> problems but
> mpi_send does not makes me think that it's either an mvapich problem or
> an mvapich specific interaction with OFED.
>
> 													thanks,
> 													Noam
>
>