RFR (M): 8227434: G1 predictions may over/underflow with high variance input

[Thomas Schatzl]

Hi all,

   ping for second review.

Thanks,
   Thomas

On 21.11.19 15:26, Stefan Johansson wrote:
> Hi Thomas,
> 
> On 2019-11-12 15:10, Thomas Schatzl wrote:
>> Hi all,
>>
>>    can I have reviews for this change that tries to fix possible 
>> underflows and overflows in our predictor use in case there is high 
>> variance input?
>>
>> I did not analyze for every case whether the issue actually happened, 
>> but changed the get_new_prediction() calls to something I believe is 
>> appropriate for the given sequence. Cases where there has already been 
>> some clamping going on were obvious of course.
>>
>> It's a bit boring to review...
>>
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8227434
>> Webrev:
>> http://cr.openjdk.java.net/~tschatzl/8227434/webrev/
> Looks good in general, me and Thomas discussed some naming suggestions 
> offline, but we are going to do that as a separate RFE. See JDK-8234574.
> 
> Thanks,
> Stefan
> 
> 
>> Testing:
>> hs-tier1-5
>>
>>
>> Thanks,
>>    Thomas