with gc+phases*=trace, we have the following log entries

[4.469s][debug][gc,phases ] GC(0) Object Copy (ms): Min: 1145.4, Avg: 860.0, Max: 1147.4, Diff: 2.0, Sum: 3440.1
[4.469s][trace][gc,phases,task] GC(0) 1146.5 1147.3 1147.4 1145.4
[4.469s][debug][gc,phases ] GC(0) Termination (ms): Min: 0.0, Avg: 0.0, Max: 0.1, Diff: 0.1, Sum: 0.1
[4.469s][trace][gc,phases,task] GC(0) 0.0 0.0 0.0 0.1
[4.469s][debug][gc,phases ] GC(0) Termination Attempts: Min: 8, Avg: 6.8, Max: 10, Diff: 2, Sum: 27
[4.469s][trace][gc,phases,task] GC(0) 10 9 8 10

The Average and Sum is recorded incorrectly. For example, Termination Attemps sum should be 37, not 27. Average is 9.2, not 6.8.

The reason is
workerDataArray.inline.hpp
template <typename T>
T WorkerDataArray<T>::sum() const {
  T s = 0;
  for (uint i = 0; i < _length; ++i) {
    if (get(i) != uninitialized()) {
      s += get(i);
    }
  }
  return s;
}
++i should be i++
Not sure if it has impact on prediction.