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From: Brian W. Barrett (bbarrett_at_[hidden])
Date: 2007-05-27 14:10:42

There are two ways you can find out if an Open MPI build has

* On the command line: You can run "ompi_info | grep Thread". If you see
mpi: no, the build doesn't support MPI_THREAD_MULTIPLE. If you see mpi:
yes, the build does support MPI_THREAD_MULTIPLE.

* At run-time. As mentioned below, if you request MPI_THREAD_MULTIPLE and
provided is only MPI_THREAD_SINGLE, then Open MPI does not have

Good luck,


> You are already there. the fact that MPI_Thread_init only provide
> MPI_THREAD_SINGLE shows that MPI_THREAD_MULTIPLE is NOT enabled in the
> library binary that you're using. Although MPI_THREAD_MULTIPLE is
> implemented in the library source code, it is only lightly tested, so it
> is
> not enabled by default.
> To enable MPI_THREAD_MULTIPLE, you need to recompile the library by first
> including --enable-mpi-threads as one of the parameters when you rerun
> ./configure as the first step of recompiling the library.
> On 5/27/07, smairal_at_[hidden] <smairal_at_[hidden]> wrote:
>> Hi,
>> I want to use threads with OpenMPI such that the threads would
>> be able to call MPI functions. For this purpose, I am using
>> MPI_Init_thread with MPI_THREAD_MULTIPLE option. But this function call
>> returns MPI_THREAD_SINGLE in the "provided" parameter indicating that
>> MPI_THREAD_MULTIPLE is not configured. Somewhere it is mentioned that
>> OpenMPI needs to be configured with --enable-mpi-threads inorder to use
>> MPI_THREAD_MULTIPLE. If true, is it possible to know whether the
>> OpenMPI (1.1.2)which I have already configured, has the option
>> "--enable-mpi-threads" already configured or not? Also, how easy or
>> difficult is it to configure --enable-mpi-threads option?
>> Please share some information on this.
>> -Thanks and Regards,
>> Sarang.
>> _______________________________________________
>> users mailing list
>> users_at_[hidden]
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