User Manual

Rev 2.2-1.0.1
Mellanox Technologies
149
• Connection management
• Receive side tag matching
• Intra-node shared memory communication
These enhancements significantly increase the scalability and performance of message commu-
nications in the network, alleviating bottlenecks within the parallel communication libraries.
The latest MXM software can be downloaded from the Mellanox website.
5.4.1 Compiling Open MPI with MXM
Step 1. Install MXM from:
• an RPM
% rpm -ihv mxm-x.y.z-1.x86_64.rpm
• a tarball
% tar jxf mxm-x.y.z.tar.bz
MXM will be installed automatically in the /opt/mellanox/mxm folder.
Step 2. Enter Open MPI source directory and run:
% cd $OMPI_HOME
% ./configure --with-mxm=/opt/mellanox/mxm <... other configure parameters...>
% make all && make install
Older versions of MLNX_OFED come with pre-installed older MXM and Open MPI versions.
Please uninstall any old MXM version prior to installing the latest MXM version in order to use
it with older MLNX_OFED versions.
Table 17 - MLNX_OFED and MXM Versions
MLNX_OFED Version MXM Version
v1.5.3-3.1.0 and v2.0-3.0.0 MXM v1.x and Open MPI compiled with MXM v1.x
v2.0-3.0.0 and higher MXM v2.x/3.x and Open MPI compiled with MXM v2.x/3.x
To check the version of MXM installed on your host, run
% rpm -qi mxm
:
 To upgrade MLNX_OFED v1.5.3-3.1.0 or later with a newer MXM:
Step 1. Remove MXM.
# rpm -e mxm
Step 2. Remove the pre-compiled Open MPI.
# rpm -e mlnx-openmpi_gcc
Step 3. Install the new MXM and compile the Open MPI with it.
To run Open MPI without MXM, run:
% mpirun -mca mtl ^mxm <...>