We've observed an excessive use of CPU system resources with OpenMPI
1.2.4 using TCP connections only on our SL5 x86_64 Cluster. Typically,
for a simple Canonical Ring Program, we're seeing between 30 and 70%
system usage.
Has anybody else noticed this sort of behaviour?
And does anybody have some
Well, I have noticed that when a process is waiting for communication
from another process the reported CPU usage remains around 100%. Is
that what you mean? I haven't explored whether these processes give way
to other active processes under the linux scheduler, nor whether I
should expect anythi
See this FAQ:
http://icl.cs.utk.edu/open-mpi/faq/?category=running#oversubscribing
OMPI by default assumes that each process has its own cpu, thus
aggressively looks for data to receive. I think there is a way to
yield the processor if you want, but I think what your seeing is
behavior yo
Has anyone had trouble using flash with openmpi? We get segfaults
when flash tries to write checkpoints.
Note that we had to compile flash+hdf5 with -mcmodel=medium (pgi
compilers) because flash statically allocates memory (bad).
Just wondering if others have ran into this before.
Brock Pal
Dear Barry and Jeff,
using OpenMPI we are experimenting something like the behaviour reported
by Barry.
Let me to introduce the context:
we are using RHEL4 U4 on 2 way, AMD Opteron dual core, nodes.
Each node is equipped with 16 GB of RAM, plus 4 GB of SWAP.
OpenMPi is 1.2.2.
Sometimes, for jo
You could try the following MCA setting in your mpirun command
--mca mpi_yield_when_idle 1
Hello all, I am using OMPI 1.2.4 on a Linux cluster (Rocks 4.2). OMPI was
configured to use the
Pathscale Compiler Suite installed in the (NFS mounted on nodes)
/home/PROGRAMS/pathscale. I am
trying to compile and run the example1.f that comes with the ACML package from
AMD, and I am
unable
