RFR: 8351146: JFR: JavaMonitorInflate event should default to no threshold and be disabled [v2]

[Coleen Phillimore]

On Thu, 6 Mar 2025 10:55:36 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> There is a threshold for inflate event. But the operation that is covered by that event is very fast, and often lock-free, so the threshold would filter many events. This would be important as we add deflation event ([JDK-8351142](https://bugs.openjdk.org/browse/JDK-8351142)), which should match inflations.
>> 
>> The only way I see this event be longer than default threshold of 10ms is transiently waiting for another thread to complete inflation.
>> 
>> Additional testing:
>>  - [x] Linux x86_64 server fastdebug, `jdk_jfr` still passes
>
> Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Disable JavaMonitorInflate and put the low default threshold
>  - Merge branch 'master' into JDK-8351146-jfr-monitor-thresholds
>  - Fix

This makes sense.  I guess this is better than leaving it as 20 and having someone know to change it to 0 in their jfc file.  Is there a command line way to enable the event, or does that require a custom jfc file?

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Marked as reviewed by coleenp (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/23891#pullrequestreview-2667185356