prun(1)
$prun -n 4 -N 2 hostname
atlas0.quadrics.com
atlas0.quadrics.com
atlas1.quadrics.com
atlas1.quadrics.com
$prun -n 4 -N 4 hostname
atlas1.quadrics.com
atlas3.quadrics.com
atlas0.quadrics.com
atlas2.quadrics.com
The -m option controls how processes are distributed over nodes. It is used in the
following example in conjunction with the -t option which tags each line of output with
the identifier of the process that wrote it.
$prun -t -n 4 -N 2 -m block hostname
0 atlas0.quadrics.com
1 atlas0.quadrics.com
2 atlas1.quadrics.com
3 atlas1.quadrics.com
$prun -t -n 4 -N 2 -m cyclic hostname
0 atlas0.quadrics.com
2 atlas0.quadrics.com
1 atlas1.quadrics.com
3 atlas1.quadrics.com
The examples so far haveused simple UNIX utilities to illustrate where processes are
run. Parallel programs are run in just the same way. The following example measures
DMA performancebetween a pair of processes on different nodes.
$prun -N 2 dping 0 1k
0: 0 bytes 2.33 uSec 0.00 MB/s
0: 1 bytes 3.58 uSec 0.28 MB/s
0: 2 bytes 3.61 uSec 0.55 MB/s
0: 4 bytes 2.44 uSec 1.64 MB/s
0: 8 bytes 2.47 uSec 3.24 MB/s
0: 16 bytes 2.55 uSec 6.27 MB/s
0: 32 bytes 2.57 uSec 12.45 MB/s
0: 64 bytes 3.48 uSec 18.41 MB/s
0: 128 bytes 4.23 uSec 30.25 MB/s
0: 256 bytes 4.99 uSec 51.32 MB/s
0: 512 bytes 6.39 uSec 80.08 MB/s
0: 1024 bytes 9.26 uSec 110.55 MB/s
The -s option instructs prun to print a summary of the resources used by the jobwhen
it finishes.
$prun -s -N 2 dping 0 32
0: 0 bytes 2.35 uSec 0.00 MB/s
5-18 RMS Commands