RFR (S/M): 8222492: G1 unnecessarily scans remembered set cards for regions that already have been evacuated

[sangheon.kim at oracle.com]

Hi Thomas,

On 5/17/19 3:31 AM, Thomas Schatzl wrote:
> Hi Kim,
>
>    thanks for your review.
>
> On Thu, 2019-05-16 at 18:45 -0400, Kim Barrett wrote:
>> On Apr 26, 2019, at 8:27 AM, Thomas Schatzl <
>> thomas.schatzl at oracle.com> wrote:
>>> CR:
>>> https://bugs.openjdk.java.net/browse/JDK-8222492
>>> Webrev:
>>> http://cr.openjdk.java.net/~tschatzl/8222492/webrev/
>>> Testing:
>>> hs-tier1-5, running the crashing test of JDK-8222426 for 5k times
>>> without failures (the crash has an occurrence of 1-2 times/1000
>>> runs).
>>>
>>> Thanks,
>>>   Thomas
>>>
>> Looks good.
>>
>> One minor nit:
>>
>> src/hotspot/share/gc/g1/g1OopClosures.inline.hpp
>>   190   // Entries in the optional collection set may become to be
>> located in the collection
>>   191   // set during incremental collection of the old generation.
>>
>> That comment needs some fixing.
>>
> I changed the comment to the following and refreshed the webrev:
>
>    // Entries in the optional collection set may start to originate from
> the collection
>    // set after one or more increments. In this case, previously
> optional regions
>    // became actual collection set regions. Filter them out here.
Looks good to me too.

Thanks,
Sangheon


>
> Thanks,
>    Thomas
>
>