HP-MPI User's Guide (11th Edition)

Understanding HP-MPI
MPI options
Chapter 3150
MPI_IC_SUFFIXES When HP-MPI is determining the availability of a
given interconnect on Linux, it tries to open libraries and find loaded
modules based on a collection of variables of the form
This is described in more detail in “Interconnect support” on page 85.
The use of interconnect environment variables MPI_ICLIB_ELAN,
MPI_ICLIB_GM, MPI_ICLIB_ITAPI, MPI_ICLIB_MX, MPI_ICLIB_UDAPL,
MPI_ICLIB_VAPI, and MPI_ICLIB_VAPIDIR has been deprecated. Refer
to “Interconnect support” on page 85 for more information on
interconnect environment variables.
MPI_COMMD MPI_COMMD routes all off-host communication through
daemons rather than between processes. The MPI_COMMD syntax is as
follows:
out_frags,in_frags
where
out_frags Specifies the number of 16Kbyte fragments available in
shared memory for outbound messages. Outbound
messages are sent from processes on a given host to
processes on other hosts using the communication
daemon.
The default value for out_frags is 64. Increasing the
number of fragments for applications with a large
number of processes improves system throughput.
in_frags Specifies the number of 16Kbyte fragments available in
shared memory for inbound messages. Inbound
messages are sent from processes on one or more hosts
to processes on a given host using the communication
daemon.
The default value for in_frags is 64. Increasing the
number of fragments for applications with a large
number of processes improves system throughput.
Only works with the -commd option. When -commd is used, MPI_COMMD
specifies daemon communication fragments.
InfiniBand environment variables
MPI_IB_CARD_ORDER Defines mapping of ranks to IB cards.