Re: [Boost-users] mpi non-blocking communication

Subject: Re: [Boost-users] mpi non-blocking communication
From: Philipp Kraus (philipp.kraus_at_[hidden])
Date: 2010-12-01 14:18:11

On 2010-11-29 17:29:22 +0100, Riccardo Murri said:

> Hi Philipp,
> 
> On Mon, Nov 29, 2010 at 4:17 PM, Philipp Kraus
> <philipp.kraus_at_[hidden]> wrote:
>> At this time I have two problems. Sometimes the programm create a error
>> with:
>> Adress not mapped (it seems that the iprobe creates the problem). I can't
>> reproduce the error.
>> 
> 
> It's difficult to give any sensible advice on this without compilable
> code; the general advice is to try to create a minimal test source
> that can reproduce the problem.  In doing the exercise, I often found
> out the problem myself...
> 
> A rough guess about your "address not mapped" error: if you are going
> to use MPI with threads, then *two* conditions must be met:
> 
> (1) You must initialize MPI with MPI_Init_thread() instead of
> MPI_Init().  The boost::mpi::communicator ctor uses MPI_Init(), so you
> must run the initialization yourself and *then* create the
> communicator object.  For instance::
> 
>       MPI_Init_thread(&argc, &argv, MPI_THREAD_SERIALIZED)
>       // ...
>       mpi::communicator world;

Do the Boost lib support the initialisation process? I have take a look 
into the Boost MPI classes, but it seems Boost calls only the 
MPI_init().
Do I understand it correct, that I must use the mpi.h for calling the 
MPI_Init_thread() or is there a boost support?

> 
> (2) Your MPI library must have been compiled with threads
> support. This is not the case with some Linux distributions, e.g.,
> Rocks 5.x, so double-check that MPI_Init_threads() actually did its
> job.

I used self-compiled libs, so that's not a problem

Thanks

Phil