RFR: 8348829: Remove ObjectMonitor perf counters [v3]

[Aleksey Shipilev]

On Tue, 18 Mar 2025 10:52:26 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> See bug for more discussion. I believe these counters are useless and come with more trouble than their worth.
>
> Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains three commits:
> 
>  - Merge branch 'master' into JDK-8348829-remove-om-counters
>  - Merge branch 'master' into JDK-8348829-remove-om-counters
>  - Counters removal

Progress: Remerged after recent updates to OM and JFR events. Found another gap: [JDK-8352256](https://bugs.openjdk.org/browse/JDK-8352256) -- I'll handle that first.

Meanwhile, CSR is updated, and [JDK-8349549](https://bugs.openjdk.org/browse/JDK-8349549) is the release note for this work.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/23326#issuecomment-2732899830