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Subject: Re: [OMPI users] MPI_THREAD_MULTIPLE support not available (OpenMPI-1.4.4)
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2012-05-17 19:07:48


You shouldn't use MPI_THREAD_MULTIPLE in Open MPI 1.4.x -- you should upgrade to 1.6. THREAD_MULTIPLE is a bit more robust in the 1.6 series for the TCP BTL. See the README for more info on THREAD_MULTIPLE.

On May 16, 2012, at 7:17 PM, devendra rai wrote:

> Hello Community,
>
> I just finished building an OpenMPI version with custom configuration (1.4.4) on a server. I do not have root privileges on the server.
>
> The server already had a "default" version on OpenMPI, which seemed to be single-threaded:
>
> ompi_info | grep Thread yields Thread support: posix (mpi: no, progress: no)
>
> For my custom build, I have MPI thread support (precisely, support for MPI_THREAD_MULTIPLE):
>
> /path/to/Custom/OpenMPI/bin/ompi_info | grep Thread yields Thread support: posix (mpi: yes, progress: no)
>
>
> Thus, I run my application as:
>
> /path/to/Custom/OpenMPI/bin/mpirun [options]...
>
> In my application, I do make a check for whether I am getting MPI_THREAD_MULTIPLE support or not:
>
> MPI_Init_thread(&argc, &argv, desired_thread_support,
> &provided_thread_support);/*Need provided_thread_support = desired_thread_support*/
>
> printf ("MPI: Requested thread support: %d, MPI thread support received: %d\n", MPI_THREAD_MULTIPLE, provided_thread_support);
>
>
> When I run the application, I get:
>
> MPI: Requested thread support: 3, MPI thread support received: 0
>
>
> I have tried lot of things, and I am not sure why this is the case.
>
>
> At the beginning of the shell script which contains /path/to/Custom/OpenMPI/bin/mpirun [options]..., I set the paths, and LD_LIBRARY_PATH:
>
> PATH=/home/raid/private/Customizations_NODELETE/OpenMPI-1.4.4/bin:$PATH
> export LD_LIBRARY_PATH=/home/raid/private/Customizations_NODELETE/gcc-4.6/lib64:/home/Morpheus/.CustomInstalledPrograms/OpenMPI-1.4.4/lib:/home/raid/private/Customizations_NODELETE/gcc-4.6/lib32
>
> So, I think that the correct version of mpirun is being used.
>
> Can someone tell me why I cannot get MPI_THREAD_MULTIPLE support?
>
> I have the same OpenMPI version on my notebook, which does provide me with MPI_THREAD_MULTIPLE.
>
> Thanks a lot.
>
> Best,
>
> Devendra
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-- 
Jeff Squyres
jsquyres_at_[hidden]
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