Filter
Top Products
7-10
Cisco SFS InfiniBand Host Drivers User Guide for Linux
OL-12309-01
Chapter 7 MVAPICH MPI
Intel MPI Benchmarks (IMB) Test Performance
When your installation is not working properly, the IMB test might lead to VAPI_RETRY_EXEC errors.
You should check the output of the PingPong, PingPing, and Sendrecv bandwidth measurements against
known good results on similar architectures and devices. Low-bandwidth values, especially at high
numbers of nodes, might indicate either severe congestion or functionality problems within the IB fabric.
Congestion can occur when the IMB test is run across a large number of nodes on fabrics with a
high-blocking factor. To test IMB benchmarks, perform the following steps:
Step 1 Download and compile the IMB test from the following URL:
http://www.intel.com/cd/software/products/asmo-na/eng/219848.htm
Step 2 Unpack the IMB test in $HOME.
Step 3 Compile the IMB test.
The following example shows how to compile the IMB test:
host1$ cd $HOME/IMB_3.0/src
host1$ make -f make_mpich MPI_HOME=/usr/local/topspin/mpi/mpich
Step 4 Log in to your local host.
Create a text file containing the names of all hosts on which to run the test. You should include at least
two hosts. These hostnames are likely to be unique to your cluster. The first name should be the name of
the host into which you are currently logged.
The following example shows one way to create a hostfile named hostfile that contains the hostnames
host1 through host4:
host1$ cat > /tmp/hostfile <<EOF
> host1
> host2
> host3
> host4
> EOF
host1$
Step 5 Run the IMB tests across multiple hosts. Use the mpirun command to launch MPI jobs. The command
uses these command-line parameters:
• The -np keyword to specify the number of processes
• The number of processes (an integer; use the number of hosts in the hostfile for this test)
• The –hostfile keyword to specify a file containing the hosts on which to run
• The name of the hostfile
• The IMB-MPI1 executable name
The following example shows how to perform the MVAPICH MPI IMB test by compiling and running
IMB-MPI1 (vary the value of the –np parameter to reflect the number of hosts that you want to run):
host1$ /usr/local/topspin/mpi/mpich/bin/mpirun_rsh -np 2 -hostfile /tmp/hostfile \
$HOME/IMB_3.0/src/IMB-MPI1