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Subject: Re: [OMPI users] Spawn problem
From: Joao Vicente Lima (joao.lima.mail_at_[hidden])
Date: 2008-03-31 10:49:11


Really MPI_Finalize is crashing and calling MPI_Comm_{free,disconnect} works!
I don't know if the free/disconnect must appear before a MPI_Finalize
for this case (spawn processes) .... some suggest ?

I use loops in spawn:
- first for testing :)
- and second because certain MPI applications don't know in advance
the number of childrens needed to complete his work.

The spawn works is creat ... I will made other tests.

thanks,
Joao

On Mon, Mar 31, 2008 at 3:03 AM, Matt Hughes
<matt.c.hughes+ompi_at_[hidden]> wrote:
> On 30/03/2008, Joao Vicente Lima <joao.lima.mail_at_[hidden]> wrote:
> > Hi,
> > sorry bring this again ... but i hope use spawn in ompi someday :-D
>
> I believe it's crashing in MPI_Finalize because you have not closed
> all communication paths between the parent and the child processes.
> For the parent process, try calling MPI_Comm_free or
> MPI_Comm_disconnect on each intercomm in your intercomm array before
> calling finalize. On the child, call free or disconnect on the parent
> intercomm before calling finalize.
>
> Out of curiosity, why a loop of spawns? Why not increase the value of
> the maxprocs argument, or if you need to spawn different executables,
> or use different arguments for each instance, why not
> MPI_Comm_spawn_multiple?
>
> mch
>
>
>
>
>
> >
> > The execution of spawn in this way works fine:
> > MPI_Comm_spawn ("./spawn1", MPI_ARGV_NULL, 2, MPI_INFO_NULL, 0,
> > MPI_COMM_SELF, &intercomm, MPI_ERRCODES_IGNORE);
> >
> > but if this code go to a for I get a problem :
> > for (i= 0; i < 2; i++)
> > {
> > MPI_Comm_spawn ("./spawn1", MPI_ARGV_NULL, 1,
> > MPI_INFO_NULL, 0, MPI_COMM_SELF, &intercomm[i], MPI_ERRCODES_IGNORE);
> > }
> >
> > and the error is:
> > spawning ...
> > child!
> > child!
> > [localhost:03892] *** Process received signal ***
> > [localhost:03892] Signal: Segmentation fault (11)
> > [localhost:03892] Signal code: Address not mapped (1)
> > [localhost:03892] Failing at address: 0xc8
> > [localhost:03892] [ 0] /lib/libpthread.so.0 [0x2ac71ca8bed0]
> > [localhost:03892] [ 1]
> > /usr/local/mpi/ompi-svn/lib/libmpi.so.0(ompi_dpm_base_dyn_finalize+0xa3)
> > [0x2ac71ba7448c]
> > [localhost:03892] [ 2] /usr/local/mpi/ompi-svn/lib/libmpi.so.0 [0x2ac71b9decdf]
> > [localhost:03892] [ 3] /usr/local/mpi/ompi-svn/lib/libmpi.so.0 [0x2ac71ba04765]
> > [localhost:03892] [ 4]
> > /usr/local/mpi/ompi-svn/lib/libmpi.so.0(PMPI_Finalize+0x71)
> > [0x2ac71ba365c9]
> > [localhost:03892] [ 5] ./spawn1(main+0xaa) [0x400ac2]
> > [localhost:03892] [ 6] /lib/libc.so.6(__libc_start_main+0xf4) [0x2ac71ccb7b74]
> > [localhost:03892] [ 7] ./spawn1 [0x400989]
> > [localhost:03892] *** End of error message ***
> > --------------------------------------------------------------------------
> > mpirun noticed that process rank 0 with PID 3892 on node localhost
> > exited on signal 11 (Segmentation fault).
> > --------------------------------------------------------------------------
> >
> > the attachments contain the ompi_info, config.log and program.
> >
> > thanks for some check,
> >
> > Joao.
> >
>
>
> > _______________________________________________
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> > users_at_[hidden]
> > http://www.open-mpi.org/mailman/listinfo.cgi/users
> >
> >
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