Geoff,
'cpu', 'slots', and 'count' all do exactly the same thing.
Tim
On Thursday 22 March 2007 03:03 pm, Geoff Galitz wrote:
> Does the hostfile understand the syntax:
>
> mybox cpu=4
>
> I have some legacy code and scripts that I'd like to move without
> modifying if possible. I understand th
Open MPI have support for one parallel debugger: Total View. I don't
know how DDT interact with the MPI library in order to get access to
the message queues, but we provide a library which allow tv to get
access to the internal representation of the message queues in Open
MPI. The access to
Thomas,
We are working on this topic at the University of Tennessee. In fact,
2 of the MPICH-V guys are now working on Open MPI on fault tolerant
aspects. With all the expertise we gathered doing MPICH-V, we decided
to take a different approach and to take advantage of the modular
archite
We use OpenMPI as our default MPI lib on our clusters. We are
starting to do some work with parallel debuggers (ddt to be exact)
and was wondering what the time line for message queue debugging
was. Just curious! Thanks.
Brock Palen
Center for Advanced Computing
bro...@umich.edu
(734)93
This problem is not related to Open MPI. Is related to the way you
use MPI. In fact there are 2 problems:
1. Buffered sends will copy the data into the attached buffer. In
your case, I think this only add one more memcpy operation to the
critical path, which might partially explain the imp
Is there known issue with buffered sends in OpenMPI 1.1.4?
I changed a single send which is called thousands of times from
MPI_SEND (& MPI_ISEND) to MPI_BSEND (& MPI_IBSEND) and my Fortran 90
code slowed down by a factor of 10.
I've looked at several references and I can't see where I'm mak
Does the hostfile understand the syntax:
mybox cpu=4
I have some legacy code and scripts that I'd like to move without
modifying if possible. I understand the syntax is supposed to be:
mybox slots=4
but using "cpu" seems to work. Does that achieve the same thing?
-geoff
Mike Houston wrote:
The main issue with this, and addressed at the end
of the report, is that the code size is going to be a problem as data
and code must live in the same 256KB in each SPE.
Just for reference, here are the stripped shared library sizes for
OpenMPI 1.2 as built on a Mercury Ce
Hi,
It is v1.2, default configuration. If it matters: OS is RHEL
(2.6.9-42.0.3.ELsmp) on x86_64.
I have noticed this for 2 apps so far, mpiBLAST and HPL, which are both
course grained.
Thanks,
Todd
On 3/22/07 2:38 PM, "Ralph Castain" wrote:
>
>
>
> On 3/22/07 11:30 AM, "Heywood, Todd" w
On 3/22/07 11:30 AM, "Heywood, Todd" wrote:
> Ralph,
>
> Well, according to the FAQ, aggressive mode can be "forced" so I did try
> setting OMPI_MCA_mpi_yield_when_idle=0 before running. I also tried turning
> processor/memory affinity on. Efffects were minor. The MPI tasks still cycle
> bewt
Ralph,
Well, according to the FAQ, aggressive mode can be "forced" so I did try
setting OMPI_MCA_mpi_yield_when_idle=0 before running. I also tried turning
processor/memory affinity on. Efffects were minor. The MPI tasks still cycle
bewteen run and sleep states, driving up system time well over us
That's pretty cool. The main issue with this, and addressed at the end
of the report, is that the code size is going to be a problem as data
and code must live in the same 256KB in each SPE. They mention dynamic
overlay loading, which is also how we deal with large code size, but
things get t
Hi,
Has anyone investigated adding intra chip Cell EIB messaging to OpenMPI?
It seems like it ought to work. This paper seems pretty convincing:
http://www.cs.fsu.edu/research/reports/TR-061215.pdf
Just for clarification: ompi_info only shows the *default* value of the MCA
parameter. In this case, mpi_yield_when_idle defaults to aggressive, but
that value is reset internally if the system sees an "oversubscribed"
condition.
The issue here isn't how many cores are on the node, but rather how
On 3/22/07, Jeff Squyres wrote:
Is this a TCP-based cluster?
yes
If so, do you have multiple IP addresses on your frontend machine?
Check out these two FAQ entries to see if they help:
http://www.open-mpi.org/faq/?category=tcp#tcp-routability
http://www.open-mpi.org/faq/?category=tcp#tcp-
LAM/MPI was able to checkpoint/restart an entire MPI job as you
mention. Open MPI is now able to checkpoint/restart as well. In the
past week I added to the Open MPI trunk a LAM/MPI-like checkpoint/
restart implementation. In Open MPI we revisited many of the design
decisions from the LAM/MP
Yes, I'm using SGE. I also just noticed that when 2 tasks/slots run on a
4-core node, the 2 tasks are still cycling between run and sleep, with
higher system time than user time.
Ompi_info shows the MCA parameter mpi_yield_when_idle to be 0 (aggressive),
so that suggests the tasks aren't swapping
For your reference:
The following cross compile/run combination with OpenMPI 1.1.4 is
currently working for me:
I'm compiling on a Debian Linux system with dual 1.3 GHz AMD Opterons
per node and an internal network of dual gigabit ethernet. With
OpenMPI compiled with Intel Fortran 9.1.04
On Mar 22, 2007, at 7:55 AM, Jeff Squyres wrote:
On Mar 15, 2007, at 12:18 PM, Michael wrote:
Situation: I'm compiling my code locally on a machine with just
ethernet interfaces and OpenMPI 1.1.2 that I built.
When I attempt to run that executable on a HPC machine with OpenMPI
1.1.2 and
On Mar 15, 2007, at 5:02 PM, Michael wrote:
I would like to hear just how portable an executable compiled against
OpenMPI shared libraries should be.
This is a hard question to answer:
1. We have not done this explicit kind of testing.
2. Open MPI's libmpi.so itself is plain vanilla C. If yo
On Mar 15, 2007, at 12:18 PM, Michael wrote:
I'm having trouble with the portability of executables compiled with
OpenMPI. I suspect the sysadms on the HPC system I'm using changed
something because I think it worked previously.
Situation: I'm compiling my code locally on a machine with just
e
Open MPI currently has minimal use of hidden "progress" threads, but
we will likely be experimenting with more usage of them over time
(previous MPI implementations have shown that progress threads can be
a big performance win for large messages, although they do tend to
add a bit of latenc
Are you using a scheduler on your system?
More specifically, does Open MPI know that you have for process slots
on each node? If you are using a hostfile and didn't specify
"slots=4" for each host, Open MPI will think that it's
oversubscribing and will therefore call sched_yield() in the d
Is this a TCP-based cluster?
If so, do you have multiple IP addresses on your frontend machine?
Check out these two FAQ entries to see if they help:
http://www.open-mpi.org/faq/?category=tcp#tcp-routability
http://www.open-mpi.org/faq/?category=tcp#tcp-selection
On Mar 21, 2007, at 4:51 P
Dear all,
I am currently working on a fault tolerant protocol for message passing
applications based on message logging.
For my experimentations, I want to implement my protocol in a MPI library.
I know that message logging protocols have already been implemented in
MPICH with MPICH-V.
I'm w
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