RFR (M): 8137082: Factor out G1 prediction code from G1CollectorPolicy and clean up

[sangheon.kim]

Hi Thomas,

On 10/14/2015 08:50 AM, Thomas Schatzl wrote:
> Hi Sangheon,
>
> On Tue, 2015-10-13 at 15:37 -0700, sangheon.kim wrote:
>> Hi Thomas,
>>
>> This is nice!
>>
>> Let me add 1 question.
>>
>> src/share/vm/gc/g1/g1Predictions.hpp
>>
>>     39   // Five or more samples yields zero (at that point we use the stddev); fewer
>>     40   // scale the sample set average linearly from 2.0 times the average to 0.5 times
>>     41   // it.
>>     42   double stddev_estimate_for_small_sample_sets(TruncatedSeq const* seq) const {
>>     43     int const samples = seq->num();
>>     44     if (samples > 4) {
>>     45       return 0.0;
>>     46     } else {
>>     47       return seq->davg() * (5 - samples) / 2.0;
>>     48     }
>>
>> 'samples' couldn't be zero?
>> If yes, line 40, '2.0 times' is not correct.
>> And I know this comment is not your change.
>    thanks for looking at this. As mentioned in the answer to Kim,
> seq->num() may actually be zero. There I also mentioned that there is
> existing code that depends on us being able to call get_new_prediction()
> with an empty sample sequence, that has been moved to a separate CR.
Okay.

Thanks,
Sangheon


>
> Thanks,
>    Thomas
>
>