Summary: Maintain a high water mark for the allocations in a space and mangle only up to that high water mark.
Reviewed-by: ysr, apetrusenko

6539517: CR 6186200 should be extended to perm gen allocation to prevent spurious OOM's from perm gen
Reviewed-by: ysr, jmasa

Summary: Default values set by cms ergonomics are set with FLAG_SET_DEFAULT so down stream the values look like the default values and affect how later parameters are set.  Set these values with FLAG_SET_ERGO instead and adjust how later parameters are interpreted.
Reviewed-by: iveresov, apetrusenko, pbk, ysr