avoiding periodic(8) during long poudriere runs

[void]

Hello stable@

How does one avoid periodic(8) during long poudriere runs?
I find that it'll cause the system to thrash if periodic
starts when poudriere is running. is there some established 
way of telling it not to run when, for example, 5 min load 
is over 2.00 ? I've seen ubuntu do similar, but am unsure of 
the exact mechanism.

tia,
--