[OMPI users] problem with MPI_[Pack|Unpack]_external

[Lisandro Dalcin]

I've just catched a problem with packing/unpacking using 'external32'
in Linux. The problem seems to be word ordering, I believe you forgot
to make the little-endian <-> big-endian conversion somewhere. Below,
an interactive session with ipython (sorry, no time to write in C)
showing the problem. Please, ignore me if this has been already
reported.

In [1]: import numpy

In [2]: from mpi4py import MPI

In [3]: print numpy.dtype('i').itemsize, MPI.INT.extent
4 4

In [4]: print numpy.dtype('b').itemsize, MPI.BYTE.extent
1 1

In [5]:

In [5]: arr1 = numpy.array([256], dtype='i') # one int, for input

In [6]: print arr1
[256]

In [7]: buf = numpy.array([0,0,0,0], dtype='b') # four bytes, auxiliar

In [8]: print buf
[0 0 0 0]

In [9]: p = MPI.INT.Pack_external('external32', arr1, buf, 0)

In [10]: print buf, repr(buf.tostring())
[0 1 0 0] '\x00\x01\x00\x00'

In [11]: arr2 = numpy.array([0], dtype='i') # one int, for output

In [12]: print arr2
[0]

In [13]: p = MPI.INT.Unpack_external('external32', buf, 0, arr2)

In [14]: print arr2
[65536]

In [15]: print arr2.byteswap()
[256]


--
Lisandro Dalcín
---
Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
PTLC - Güemes 3450, (3000) Santa Fe, Argentina
Tel/Fax: +54-(0)342-451.1594

[OMPI users] Building Open MPI 1.1.1 on OS X with ifort and icc support

[Josh Durham]

Below are the changes needed to build OMPI on OSX with ifort and  
icc.  Basically, the Xgrid component doesn't have a libtool tag  
defined for ObjC code.  Adding this makes it consistent with the rest  
of the build - all the other Makefiles has --tag=CC.  This was  
configured with './configure CC=icc CXX=icpc'


In orte/mca/pls/xgrid/Makefile.in:
215c215
< LTOBJCCOMPILE = $(LIBTOOL) --mode=compile $(OBJC) $(DEFS) \
---
> LTOBJCCOMPILE = $(LIBTOOL) --tag=CC --mode=compile $(OBJC) $(DEFS) \
219c219
< OBJCLINK = $(LIBTOOL) --mode=link $(OBJCLD) $(AM_OBJCFLAGS) \
---
> OBJCLINK = $(LIBTOOL) --tag=CC --mode=link $(OBJCLD) $ 
(AM_OBJCFLAGS) \


I'll leave it up to the developers to figure out how to get the  
automake stuff to generate this properly.  I have no clue.


- Josh

[MTT users] Running the v1.1 nightly

[Josh Hursey]

Has anyone been using MTT to test the v1.1 nightly?

I have been trying to run the [trivial,ibm] tests against  
[trunk,v1.2,v1.1]. MTT will build all the sources and all the tests  
with all the sources. It will then run the trivial tests against all  
three sources, but only the ibm tests against the trunk and v1.2.


I looked at the logs produced and there didn't seem to be any errors  
with the ibm+v1.1 test build. Would there be any other reason this  
would happen?



Josh Hursey
jjhur...@open-mpi.org
http://www.open-mpi.org/

Re: [OMPI users] Need help in Perl with MPI

[Prakash Velayutham]

Hello,

Yes. We do this all the time. But you should understand that the MySQL
database server becomes your bottle neck in this parallel environment.
In our case, we run the database servers also in parallel on the
scheduler assigned nodes. But this is very much application-specific.

Thanks,
Prakash

Abhishek Pratap wrote:
> Hello All
>
> can i execute a perl program over MPI. My program has to access Mysql
> database for accessing the data during runtime.
>
> Is it Possible here  in perl i can use Perl's Parallel::MPI (or
> Parallel::MPI::Simple) but will they be able to access the mysql database
> simultaneously from  the server.
>
> Regards,
> Abhishek
>
> On 9/29/06, Prakash Velayutham  wrote:
>>
>> Use Perl's Parallel::MPI (or Parallel::MPI::Simple) module. Get it from
>> CPAN. Documentation should be good enough to start with.
>>
>> Prakash
>>
>> Abhishek Pratap wrote:
>> > Can i execute a code written in perl over with MPI.
>> >
>> > My code also access a database present locally on the server.
>> >
>> > I am  new to this field . Looking for some help
>> >
>> > Regards,
>> > Abhishek 

Re: [OMPI users] Need help in Perl with MPI

[Abhishek Pratap]

Hello All


can i execute a perl program over MPI. My program has to access Mysql
database for accessing the data during runtime.

Is it Possible here  in perl i can use Perl's Parallel::MPI (or
Parallel::MPI::Simple) but will they be able to access the mysql database
simultaneously from  the server.


Regards,
Abhishek


On 9/29/06, Prakash Velayutham  wrote:


Use Perl's Parallel::MPI (or Parallel::MPI::Simple) module. Get it from
CPAN. Documentation should be good enough to start with.

Prakash

Abhishek Pratap wrote:
> Can i execute a code written in perl over with MPI.
>
> My code also access a database present locally on the server.
>
> I am  new to this field . Looking for some help
>
> Regards,
> Abhishek
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--
-
Abhishek Pratap
Third Year
Bioinformatics
School of Biotechnology & Chemical Eng
VIT
Vellore.
INDIA
Ph:   (91)-416-3206020
Mob: (91)-9843181010

Re: [OMPI users] Need help in Perl with MPI

[Prakash Velayutham]

Use Perl's Parallel::MPI (or Parallel::MPI::Simple) module. Get it from
CPAN. Documentation should be good enough to start with.

Prakash

Abhishek Pratap wrote:
> Can i execute a code written in perl over with MPI.
>
> My code also access a database present locally on the server.
>
> I am  new to this field . Looking for some help
>
> Regards,
> Abhishek 

[OMPI users] Need help in Perl with MPI

[Abhishek Pratap]

Can i execute a code written in perl over with MPI.

My code also access a database present locally on the server.

I am  new to this field . Looking for some help


Regards,
Abhishek

--
-
Abhishek Pratap
Third Year
Bioinformatics
School of Biotechnology & Chemical Eng
VIT
Vellore.
INDIA
Ph:   (91)-416-3206020
Mob: (91)-9843181010