MVAPICH

Profiling Wrappers

Only precompiled wrappers (see MPI wrapper libraries) are supported with mpi_f08 for MVAPICH 4.0. Contact Forge Support should you need to compile wrappers for this MPI version.

Message Queue Debugging

To enable message Queue Support, compile MVAPICH with the flags --enable-debuginfo --enable-shared. The debug info flag is not enabled by default.

Memory Debugging

Memory debugging in Linaro DDT interferes with the on-demand connection system used by MVAPICH2 and MVAPICH 3.0 above a threshold process count, and applications fail to start.

The default threshold value is 64.

As a workaround, set the environment variable MV2_ON_DEMAND_THRESHOLD or MVP_ON_DEMAND_THRESHOLD (MVAPICH 3.0) to the maximum job size you expect on your system and Linaro DDT can work with memory debugging enabled for all jobs.

Do not set this as a system-wide setting because it might increase startup times for jobs and memory consumption.

Scalable Launch

MVAPICH2 and MVAPICH 3.0 offer mpirun_rsh instead of mpirun as a scalable launcher binary.

To use this with Linaro DDT, go to the System page (File ‣ Options, or Linaro Forge ‣ Preferences on Mac OS X).
Select Override default mpirun path and enter mpirun_rsh.
Add -hostfile <hosts> in the mpirun_rsh arguments field in the Run window. <hosts> is the name of your hosts file.