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Re: mpi 1.1.1 released
From: |
c. |
Subject: |
Re: mpi 1.1.1 released |
Date: |
Mon, 6 Jan 2014 18:17:26 +0100 |
On 6 Jan 2014, at 12:03, c. <address@hidden> wrote:
>
> On 5 Jan 2014, at 16:31, Sukanta Basu <address@hidden> wrote:
>
>> Hi Carlo,
>>
>> I ran the code for ~100,000 steps. I do not see any leak. I did the
>> following:
>>
>> 1. mkoctfile prova.cc
>> 2. octave < memory_test.m
>>
>> Do you think you are getting closer to resolve this issue?
>
> I'm just trying to convert your script to something more portable (i.e., that
> I can run on my mac)
> as on BSD/Darwin there is no simple equivalent of the 'free' command ...
>
>> Cheers,
>> Sukanta
> c.
Hi Sukanta,
I think I got a clue of what could be the problem:
In order to send/receive arrays what is currently done is to create a derived
contigous datatype
MPI_Datatype fortvec;
MPI_Type_contiguous (nitem, TSnd, &fortvec);
MPI_Type_commit (&fortvec);
Then the array data is sent via
info = MPI_Send (LBNDA1, 1, fortvec, rankrec_ptr[i], tanktag[4], comm);
Once the communication is done, the datatype should be cleared with
MPI_Type_free (&fortvec);
but this latter call seems to be missing.
The leak is very small (1 word per message being sent), but over a long number
of iterations
this may be causing (at least part) of the memory usage you reported.
I see two possible fixes:
* add a call to MPI_Type_free for each MPI_Type_commit in the code
* get rid of the derived datatype and use
MPI_Send (LBNDA1, nitem, TSnd, rankrec_ptr[i], tanktag[4], comm);
instead
The modified version of the package in the attachment implements the latter
option,
could you please check whether it works any better for you?
Does anyone see a good reason to prefer the former strategy of creating a
derived
contiguous datatype each type an array is sent?
c.
mpi.tgz
Description: Binary data
- Re: mpi 1.1.1 released, Michael Creel, 2014/01/02
- Re: mpi 1.1.1 released, c., 2014/01/02
- Re: mpi 1.1.1 released, Michael Creel, 2014/01/02
- Re: mpi 1.1.1 released, c., 2014/01/02
- Message not available
- Re: mpi 1.1.1 released, Michael Creel, 2014/01/03
- Message not available
- Re: mpi 1.1.1 released, c., 2014/01/03
- Re: mpi 1.1.1 released, c., 2014/01/03
- Message not available
- Re: mpi 1.1.1 released, c., 2014/01/03
- Re: mpi 1.1.1 released, c., 2014/01/05
- Message not available
- Re: mpi 1.1.1 released, c., 2014/01/06
- Re: mpi 1.1.1 released,
c. <=
- Message not available
- Re: mpi 1.1.1 released, Michael Creel, 2014/01/06
- Re: mpi 1.1.1 released, c., 2014/01/06
- Message not available
- Re: mpi 1.1.1 released, c., 2014/01/07
- Re: mpi 1.1.1 released, c., 2014/01/07
- Re: mpi 1.1.1 released, Doug Stewart, 2014/01/07
- Re: mpi 1.1.1 released, c., 2014/01/07
- Re: mpi 1.1.1 released, Doug Stewart, 2014/01/07
- Re: mpi 1.1.1 released, Doug Stewart, 2014/01/07
- Message not available
- Message not available
- Re: mpi 1.1.1 released, c., 2014/01/07
- Re: mpi 1.1.1 released, c., 2014/01/07