Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: Re: [OMPI users] Deadlocks and warnings from libevent when using MPI_THREAD_MULTIPLE
From: Jeffrey A Cummings (Jeffrey.A.Cummings_at_[hidden])
Date: 2014-04-28 11:03:36


Wouldn't you save yourself work and your users confusion if you disabled
options that don't currently work?

Jeffrey A. Cummings
Engineering Specialist
Performance Modeling and Analysis Department
Systems Analysis and Simulation Subdivision
Systems Engineering Division
Engineering and Technology Group
The Aerospace Corporation
571-307-4220
jeffrey.a.cummings_at_[hidden]

From: Ralph Castain <rhc_at_[hidden]>
To: Open MPI Users <users_at_[hidden]>,
Date: 04/25/2014 05:40 PM
Subject: Re: [OMPI users] Deadlocks and warnings from libevent when
using MPI_THREAD_MULTIPLE
Sent by: "users" <users-bounces_at_[hidden]>

We don't fully support THREAD_MULTIPLE, and most definitely not when using
IB. We are planning on extending that coverage in the 1.9 series

On Apr 25, 2014, at 2:22 PM, Markus Wittmann <markus.wittmann_at_[hidden]>
wrote:

> Hi everyone,
>
> I'm using the current Open MPI 1.8.1 release and observe
> non-deterministic deadlocks and warnings from libevent when using
> MPI_THREAD_MULTIPLE. Open MPI has been configured with
> --enable-mpi-thread-multiple --with-tm --with-verbs (see attached
> config.log)
>
> Attached is a sample application that spawns a thread for each process
> after MPI_Init_thread has been called. The thread then calls MPI_Recv
> which blocks until the matching MPI_Send is called just before
> MPI_Finalize is called in the main thread. (AFAIK MPICH uses such kind
> of facility to implement a progress thread) Meanwhile the main thread
> exchanges data with its right/left neighbor via ISend/IRecv.
>
> I only see this, when the MPI processes run on separate nodes like in
> the following:
>
> $ mpiexec -n 2 -map-by node ./test
> [0] isend/irecv.
> [0] progress thread...
> [0] waitall.
> [warn] opal_libevent2021_event_base_loop: reentrant invocation. Only one
event_base_loop can run on each event_base at once.
> [1] isend/irecv.
> [1] progress thread...
> [1] waitall.
> [warn] opal_libevent2021_event_base_loop: reentrant invocation. Only one
event_base_loop can run on each event_base at once.
>
> <no further output...>
>
> Can anybody confirm this?
>
> Best regards,
> Markus
>
> --
> Markus Wittmann, HPC Services
> Friedrich-Alexander-Universität Erlangen-Nürnberg
> Regionales Rechenzentrum Erlangen (RRZE)
> Martensstrasse 1, 91058 Erlangen, Germany
> http://www.rrze.fau.de/hpc/
> <info.tar.bz2><test.c>_______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users

_______________________________________________
users mailing list
users_at_[hidden]
http://www.open-mpi.org/mailman/listinfo.cgi/users