RFR: 8269823: JFR: Eliminate 'is_large' check for native JFR event if the size range is certain [v2]

[Erik Gahlin]

On Sat, 3 Jul 2021 00:46:13 GMT, Denghui Dong <ddong at openjdk.org> wrote:

>> Hi,
>> 
>> Could I have a review of this improvement that eliminates 'is_large' check if the event size range is certain?
>> 
>> JDK-8246260 introduced event large checks to reduce the recording size.
>> This check could be eliminated at compile/build time when one of the following conditions is satisfied:
>> 1. if the max size is < 128
>> 2. if the min size is >= 128
>> 
>> The max size and the min size could be computed for the most native events at the generation phase.
>> 
>> And I think this improvement may also be done for JDK events.
>
> Denghui Dong has updated the pull request incrementally with one additional commit since the last revision:
> 
>   refactor

This complicates the implementation with what I would assume negligible impact on performance. Do you have measurements that proves that throughput is improved significantly with this change?

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PR: https://git.openjdk.java.net/jdk/pull/4670