Without this patch, the pmap -XX call fails on openSUSE Leap
distributions as those have a fairly ancient procps version that
does not support the -XX parameter. A pure python implementation
is more portable, faster and even shorter than the subprocess
call.
Closes-Bug: #1716066
Change-Id: I2fdb457e65359a1c9d40452c922cfdca0e6e74dc