Currently G1 uses the (random) constant InitialSurvivorRate for survival rate for initializing newly used young regions.

While using InitialSurvivorRate is good because it is fairly conservative (0.4), it is bad for many situations because it has nothing to do with the actual application behavior.

Further particularly since values at the end of this array are seldom updated, the value hardly changes, inhibiting young gen expansion somewhat.

The suggestion is, when expanding the array, to use the survivor rate of the last element in the array.