RFR: 8286707: JFR: Don't commit JFR internal jdk.JavaMonitorWait events [v2]

[Joakim Nordström]

On Tue, 18 Oct 2022 00:50:42 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> There exist a general exclusion/inclusion mechanism already. But it is an all-or-nothing proposition. This particular case is a thread that we can't exclude because it runs the periodic events, upon being notified. It is the notification mechanism to run the periodic events that trigger this large amount of unnecessary MonitorWait events. Even should we change it to some util.concurrent construct, we are only pushing the problem, because we might be instrumenting them later too. To work with the existing exclusion mechanism, the system would have to introduce an additional thread, which will be excluded, which only handles the notification, and then by some other means triggers another periodic thread (included) to run the periodic events.
>
> @mgronlun my request is that this filtering be done inside the commit logic by the JFR code, not at the site where the event is generated - ie this internal-jfr-event filtering is internalized into the JFR code.

Thank you for reviewing and comments, @dholmes-ora, @egahlin and @mgronlun!

Would anyone of you sponsor this as well? Thanks!

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PR: https://git.openjdk.org/jdk/pull/8883