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Subject: Re: [OMPI users] Programming help required in Interleavingcomputation+communication !
From: Jeff Squyres (jsquyres_at_[hidden])
Date: 2009-11-30 20:02:23


With a quick glance through your code, it doesn't look like there is
synchronization between the (Tid == NCORES-1) thread and the other
threads. Is that intentional?

On Nov 19, 2009, at 3:03 PM, souvik bhattacherjee wrote:

> Hi all,
>
> I'm trying to interleave computation with communication. As a
> result, I have resorted to using MPI with POSIX threads. Primarily,
> I am trying to communicate a partial vector v3 while computing an
> inner product v1*v2 (mod q). To give you an idea of the platform and
> the libraries:
> 1. Intel dual-socket quadcore m/c (total 8 cores/machine)
> 2. openmpi 1.3.3 (separate installations on ict6 and ict4 machines)
> 3. lib64gmp3 4.3.1
> 4. gcc 4.3.2
> 5. interconnect: Gigabit ethernet
>
> I have used a single thread for most of the communication and the
> remaining 7 threads for computation. Perhaps, this portion of the
> code has gone wrong somewhere and the program terminates with the
> following error message.
>
> $ mpicc test-vecvecmul.c -lgmp -pthread -Wall -o tvmul
>
> $ mpirun --prefix /usr/local/openmpi-1.3.3/ -np 2 --host ict6,ict4 ./
> tvmul
>
> [err] event_queue_remove: 0xc1d6b0(fd 10) not on queue 8
> [err] event_queue_remove: 0xc1d6b0(fd 10) not on queue 8
> [ict6][[21545,1],0][../../../../../ompi/mca/btl/tcp/btl_tcp_frag.c:
> 216:mca_btl_tcp_frag_recv] mca_btl_tcp_frag_recv: readv failed:
> Connection reset by peer (104)
> --------------------------------------------------------------------------
> mpirun has exited due to process rank 1 with PID 17154 on
> node ict4 exiting without calling "finalize". This may
> have caused other processes in the application to be
> terminated by signals sent by mpirun (as reported here).
> --------------------------------------------------------------------------
>
> The code is attached along with. Please suggest where in the code
> have I gone wrong. Also, a more efficient way of interleaving (if
> exists) is something that I am interested in.
>
> **** Can anyone suggest a good tutorial sort of thing where I can
> get to know about programming in MPI with POSIX threads/OpenMP.
>
> Regards,
> --
> Souvik
>
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-- 
Jeff Squyres
jsquyres_at_[hidden]