[jdk17u-dev] RFR: 8369992: JFR: Disable Placeholder-, LoaderConstraints- and ProtectionDomainCacheTableStatistics in default.jfc

[Matthias Baesken]

On Sun, 26 Oct 2025 18:44:57 GMT, Goetz Lindenmaier <goetz at openjdk.org> wrote:

> I backport this for parity with 17.0.18-oracle.
> 
> First, there was the attempt to delete these events, see backport of https://bugs.openjdk.org/browse/JDK-8291733: Remove JFR events that expose hashtable
> 
> @eghalin pointed out to me that Oracle reverts this (See [JDK-8369975](https://bugs.openjdk.org/browse/JDK-8369975) [BACKOUT BACKPORT] Remove JFR events that expose hashtable) and instead disables the events, 
> see also comment in https://github.com/openjdk/jdk17u-dev/pull/4047 
> 
> This now implements the backport according to that comment.
> 
> Thanks again, Eric, for informing about this.

looks okay but see my comment .

The JBS issue https://bugs.openjdk.org/browse/JDK-8369992 says the events 'add no value' and 'may cause performance regressions'.
So I wonder why we keep them in profile.jfc , at least in this commit  profile.jfc was touched too
https://github.com/openjdk/jdk/commit/b7d2bde8e37817e827e685bd675b075c1f29b4c2

(in jdk head they are gone completely).

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Marked as reviewed by mbaesken (Reviewer).

PR Review: https://git.openjdk.org/jdk17u-dev/pull/4108#pullrequestreview-3387500179
PR Comment: https://git.openjdk.org/jdk17u-dev/pull/4108#issuecomment-3455308474