Open MPI logo

Open MPI User's Mailing List Archives

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

Subject: Re: [OMPI users] [EXTERNAL] MPI_THREAD_SINGLE vs. MPI_THREAD_FUNNELED
From: Paul Kapinos (kapinos_at_[hidden])
Date: 2013-10-23 13:56:17


AFAIK,
since 1.7.x the MPI_THREAD_SERIALIZED is available by default, anf for
MPI_THREAD_MULTIPLE you have to set the --with-verbs flag (1.6.x and older:
--with-openib) at configure time.

Note that activating MPI_THREAD_MULTIPLE silently disable InfiniBand, so your
program may get very bad performance without being verbose.

Best

Paul

Is there no bug in MPI_THREAD_MULTIPLE implementation in 1.7.2 and 1.7.3? My
test program just hang now

On 10/23/13 19:47, Jeff Hammond wrote:
> On Wed, Oct 23, 2013 at 12:02 PM, Barrett, Brian W <bwbarre_at_[hidden]> wrote:
>> On 10/22/13 10:23 AM, "Jai Dayal" <dayalsoap_at_[hidden]> wrote:
> <snip>
>> I'm asking because I'm using an open_mpi build ontop of infiniband, and the
>> maximum thread mode is MPI_THREAD_SINGLE.
>>
>>
>> That doesn't seem right; which version of Open MPI are you using?
>
> The last time I looked at this, OpenMPI only supported
> MPI_THREAD_SINGLE by default and if you ask for any higher thread
> level, you get MPI_THREAD_MULTIPLE, which requires a configure-time
> switch.
>
> Maybe something has changed dramatically more recently than I tested.
> Squyres told me some thread-oriented refactoring was going on. All of
> this was over a year ago so it is entirely reasonable for me to be
> wrong about all of this.
>
> Jeff
>

-- 
Dipl.-Inform. Paul Kapinos   -   High Performance Computing,
RWTH Aachen University, Center for Computing and Communication
Seffenter Weg 23,  D 52074  Aachen (Germany)
Tel: +49 241/80-24915