Hi all - and sorry for the multiple postings, but I have more information.
1: After a reboot of two nodes I ran again, and the inter-node freeze didn't
happen until the third iteration. I take that to mean that the basic
communication works, but that something is saturating. Is there some notion
o
Thanks for your suggestion Gus, we need a way of debugging what is going on.
I am pretty sure the problem lies with our cluster configuration. I know MPI
simply relies on the underlying network. However, we can ping and ssh to all
nodes (and in between and pair as well) so it is currently a mystery
I am observing differences in floating-point results from an application
program that appear to be related to whether I link with OpenMPI 1.4.3 or
MVAPICH 1.2.0. Both packages were built with the same installation of Intel
11.1, as well as the application program; identical flags passed to the
Hi Ole, Eugene
For what it is worth, I tried Ole's program here,
as Devendra Rai had done before.
I ran it across two nodes, with a total of 16 processes.
I tried mca parameters for openib Infiniband,
then for tcp on Gigabit Ethernet.
Both work.
I am using OpenMPI 1.4.3 compiled with GCC 4.1.2 on
The bottom of the MPI_Cart_coords man page (in SVN trunk as well as some
releases) states:
The inverse mapping, rank-to-coordinates translation is provided by
MPI_Cart_coords.
Although that is true, we are already in the man page for MPI_Cart_coords
and so the reverse is the mapping from coo
Hi Eugene
You're right, it is blocking send, buffers can be reused after MPI_Send
returns.
My bad, I only read your answer to Sebastien and Ole
after I posted mine.
Could MPI run out of [internal] buffers to hold the messages, perhaps?
The messages aren't that big anyway [5000 doubles].
Could
Greetings Scott,
The NSLog call should be no big deal since it is provided by the Cocoa
frameworks and is inherent to Objective C.
The mpicc compiler may be a different thing. It may not recognize that it
supposed to be calling gcc to compile in Objective-C mode and not in pure ISO
C-99.
On 9/18/2011 9:12 AM, Evghenii Gaburov wrote:
Hi All,
Update to the original posting: METHOD4 also resulted in a deadlock on system HPC2 after
5h of run with 32 MPI tasks; also, "const int scale=1;" was missing in the code
snippet posted above.
--Evghenii
Message: 2
Date: Sun, 18 Sep 2011
Hi Ole
You could try the examples/connectivity.c program in the
OpenMPI source tree, to test if everything is alright.
It also hints how to solve the buffer re-use issue
that Sebastien [rightfully] pointed out [i.e., declare separate
buffers for MPI_Send and MPI_Recv].
Gus Correa
Sébastien Bois
Should be fine. Once MPI_Send returns, it should be safe to reuse the
buffer. In fact, the return of the call is the only way you have of
checking that the message has left the user's send buffer. The case
you're worried about is probably MPI_Isend, where you have to check
completion with an
Hello,
Is it safe to re-use the same buffer (variable A) for MPI_Send and MPI_Recv
given that MPI_Send may be eager depending on
the MCA parameters ?
>
>
> Sébastien
>
> De : users-boun...@open-mpi.org [users-boun...@open-mpi.org] de la part de
> Ole
On Sep 19, 2011, at 8:37 AM, Sébastien Boisvert wrote:
> You need to call MPI_Init before calling MPI_Init_thread.
This is incorrect -- MPI_INIT_THREAD does the same job as MPI_INIT, but it
allows you to request a specific thread level.
> According to http://cw.squyres.com/columns/2004-02-CW-MP
+1
You'll probably have to run "mpicc --showme" to see all the flags that OMPI is
passing to the underlying compiler, and use those (or equivalents) to the ObjC
compiler.
On Sep 19, 2011, at 8:34 AM, Ralph Castain wrote:
> Nothing to do with us - you call a function "NSLog" that Objective C d
Hello,
You need to call MPI_Init before calling MPI_Init_thread.
According to http://cw.squyres.com/columns/2004-02-CW-MPI-Mechanic.pdf (Past
MPI Mechanic Columns written by Jeff Squyres)
only 3 functions that can be called before calling MPI_Init and they are:
- MPI_Initialized
- MPI_Finalized
Nothing to do with us - you call a function "NSLog" that Objective C doesn't
recognize. That isn't an MPI function.
On Sep 18, 2011, at 8:20 PM, Scott Wilcox wrote:
> I have been asked to convert some C++ code using Open MPI to Objective C and
> I am having problems getting a simple Obj C progr
On 14-Sep-11 12:59 PM, Jeff Squyres wrote:
> On Sep 13, 2011, at 6:33 PM, kevin.buck...@ecs.vuw.ac.nz wrote:
>
>> there have been two runs of jobs that invoked the mpirun using these
>> OpenMPI parameter setting flags (basically, these mimic what I have
>> in the global config file)
>>
>> -mca btl
Hello Ole
I ran your program on open-mpi-1.4.2 five times, and all five times, it
finished successfully.
So, I think the problem was with the version of mpi.
Output from your program is attached. I ran on 3 nodes:
$home/OpenMPI-1.4.2/bin/mpirun -np 3 -v --output-filename mpi_testfile
./mpi_t
The test program is available here:
http://code.google.com/p/pypar/source/browse/source/mpi_test.c
Hopefully, someone can help us troubleshoot why communications stop when
multiple nodes are involved and CPU usage goes to 100% for as long as we
leave the program running.
Many thanks
Ole Nielsen
please unsubscribe me from this maillist.
Thank you,
-Bill Lane
From: users-boun...@open-mpi.org [users-boun...@open-mpi.org] on behalf of Ole
Nielsen [ole.moller.niel...@gmail.com]
Sent: Monday, September 19, 2011 1:39 AM
To: us...@open-mpi.org
Subject: Re: [OMP
Further to the posting below, I can report that the test program (attached -
this time correctly) is chewing up CPU time on both compute nodes for as
long as I care to let it continue.
It would appear that MPI_Receive which is the next command after the print
statements in the test program.
Has an
Hello Community,
I am building an application which uses MPI_Ssend(...) and MPI_Recv(...)
in threads. So, there is more than one thread which invokes MPI
functions.
Based on Jeff's inputs, I rebuilt open-mpi with threads support:
./configure --enable-mpi-threads=yes --with-threads=posix ...
Hi all
We have been using OpenMPI for many years with Ubuntu on our 20-node
cluster. Each node has 2 quad cores, so we usually run up to 8 processes on
each node up to a maximum of 160 processes.
However, we just upgraded the cluster to Ubuntu 11.04 with Open MPI 1.4.3
and and have come across a
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