Using the -Z Option

The -Z option causes the CRE to organize a job's processes into subsets of a specified size and to group all processes in a subset on the same node. You specify the subset size with a numerical argument to -Z. For example,

% mprun -Z 3 -np 8 a.out

groups the job's processes by threes. These groups may be distributed onto different nodes, but there is no guarantee that they will be; two or more groups may be started on the same CPU.

The -Z option is incompatible with the -S and -W options.