RFR: 8274191: Improve g1 evacuation failure injector performance [v3]

[Albert Mingkun Yang]

On Fri, 24 Sep 2021 09:31:52 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

>> Hi all,
>> 
>>   can I have reviews for this change that improves evacuation failure injector performance to be usable for pinned region performance work?
>> 
>> The suspected reason I think why performance is so bad (image in the CR), is that the unsynchronized reads and writes to `G1YoungGCEvacFailureInjector::_evacuation_failure_object_count` cause massive performance issue if done millions of times.
>> 
>> This change makes that counter thread-local, fixing that issue completely.
>> 
>> I initially had a prototype using a `THREAD_LOCAL`, but when testing I had the feeling that this is/was slightly slower and I thought that adding a variable to every thread where most do not use them seems to be a waste.
>> 
>> Testing: local testing, GHA
>> 
>> Thanks,
>>   Thomas
>
> Thomas Schatzl has updated the pull request incrementally with one additional commit since the last revision:
> 
>   ayang review

Marked as reviewed by ayang (Reviewer).

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PR: https://git.openjdk.java.net/jdk/pull/5650