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From: Brock Palen (brockp_at_[hidden])
Date: 2006-06-13 11:07:41


Here are the results with -mca mpi_leave_pinned
The results are as expected, they are exactly similar to the mpich
results. Thank you for the help. I have attached a plot with all
three and the raw data for anyones viewing pleasure.

Im still curious about does mpi_leave_pinned affect real jobs if its
not included? for the most part for large messages of the size used
in this test will never be seen. So the effect should be
negligible? Clarification?
Note I am a admin not a MPI programmer have very lax experience with
real code.


Brock Palen
Center for Advanced Computing
brockp_at_[hidden]
(734)936-1985

On Jun 13, 2006, at 10:38 AM, Brock Palen wrote:

> Ill provide new numbers soon with the --mac mpi_leave_pinned 1
> I'm currious how does this affect real application performace? This
> ofcourse is a synthetic test using NetPipe. For regular apps that
> move decent amounts of data but want low latency more.
> Will that be affected?
>
> Brock Palen
> Center for Advanced Computing
> brockp_at_[hidden]
> (734)936-1985
>
>
> On Jun 13, 2006, at 10:26 AM, George Bosilca wrote:
>
>> Unlike mpich-gm, Open MPI does not keep the memory pinned by default.
>> You can force this by ading the "--mca mpi_leave_pinned 1" to your
>> mpirun command or by adding it into the Open MPI configuration file
>> as specified on the FAQ (section performance). I think that should be
>> the main reason what you're seeing a such degradation of
>> performances.
>>
>> If this does not solve your problem, can you please provide the new
>> performance as well as the output of the command "ompi_info --param
>> all all".
>>
>> Thanks,
>> george.
>>
>> On Jun 13, 2006, at 10:01 AM, Brock Palen wrote:
>>
>>> I ran a test using openmpi-1.0.2 on OSX vs mpich-1.2.6 from
>>> mryicom and i get lacking results from OMPI,
>>> at point point there is a small drop in bandwidth for both MPI
>>> libs, but open mpi does not recover like mpich, and further on you
>>> see a decreese in bandwidth for OMPI on gm.
>>>
>>> I have attached in png and the outputs from the test (there are
>>> two for OMPI )
>>> <bwMyrinet.png>
>>> <bwOMPI.o1969>
>>> <bwOMPI.o1979>
>>> <bwMPICH.o1978>
>>>
>>> Brock Palen
>>> Center for Advanced Computing
>>> brockp_at_[hidden]
>>> (734)936-1985
>>>
>>>
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>>> users mailing list
>>> users_at_[hidden]
>>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>
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bwmyirnet.png