There is a race condition between expect script consuming the output
from slabtop. There were a sequences of lines that looked like
^\d+ ... \s*
with the last \s* consuming the first space on the start of the line.
However if the line takes too long to print, then expect stops there and
the space at the start of the subsquent line does not match.
The solution is a \s* at the start ofthe line.
procps works well on Linux, on other arches there are some strange
differences due to their emulation of procfs which is not 100%
Disabling checks for non-linux until that can be sorted out.