brooklyncentral/brooklyn — pull request #296 by ahgittin (2012-09-03 12:31:07+00:00)
Title: one more change, to really fix the potential thrashing problem (tests we...

...re broken by prev commit)!

this essentially reverts the previous change (ceiling/floor) then simplifies the maths so it's clear why that's wanted,
then does an extra, explicit, check to see if we would cause thrashing.