Open MPI logo

Open MPI User's Mailing List Archives

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

Subject: Re: [OMPI users] OpenMPI 1.8.1 runs more OpenMP Threads on the same core
From: Ralph Castain (rhc.openmpi_at_[hidden])
Date: 2014-06-27 06:30:09


You should add this to your cmd line:

--map-by core:pe=4

This will bind each process to 4 cores

Sent from my iPhone

> On Jun 27, 2014, at 5:22 AM, Luigi Santangelo <luigi.santangelo_at_[hidden]> wrote:
>
> Hi all,
> My system is a 64 core, with Debian 3.2.57 64 bit, GNU gcc 4.7, kernel Linux 3.2.0 and OpenMPI 1.8.1.
> I developed an application to matching proteins files using OpenMP+OpenMPI. I compiled souce code with -fopenmp flag, I set OMP_NUM_THREADS=4 then I ran binary with mpiexec -np 16.
> When the program runs, the top command show me that only 16 core are used. If I use the previous of OpenMPI (1.6.5) it works fine. Must I set anything in the new version? Where I wrong?
>
> Thanks in advance
>
> Luigi
>
> _______________________________________________
> users mailing list
> users_at_[hidden]
> Subscription: http://www.open-mpi.org/mailman/listinfo.cgi/users
> Link to this post: http://www.open-mpi.org/community/lists/users/2014/06/24712.php