RFR: 8274178: G1: Occupancy value in IHOP logging and JFR event is inaccurate [v4]

[Stefan Karlsson]

On Thu, 13 Nov 2025 10:37:43 GMT, Albert Mingkun Yang <ayang at openjdk.org> wrote:

>> I.e. the identifier `jfr` is throughout the GC code (from quick searching) always associated to `events` or the `tracer`. We already use names like `*JFRTracer*` (in G1) or `_jfr_tracer` (in ZGC) to (apparently to me) make it clear that the related code is about jfr.
>> 
>> To me the term tracing is too generic, whenever I read such a name I always need to think about what kind of tracing for what is actually meant, as opposed to printing a (text) log message. With something like "jfr" in the name it is very clear that this is not something generic.
>
>> Because this is what the method does.
> 
> But we don't/can't know that info in this context.
> 
> I'd slightly leaned towards the old name, as there is no jfr in the current context. (Ofc, that's a diff story if `G1NewTracer` is renamed to `G1NewJfrTracer`, or sth.) Very subjective; up to you.

FWIW, the term "Tracer" comes from the time when JFR was a closed-source feature. The open-source code used the term "tracer" as some-sort of an interface. JFR was the closed-source implementation of the "tracer".

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PR Review Comment: https://git.openjdk.org/jdk/pull/28175#discussion_r2523320791