[jdk17u-dev] RFR: 8291733: Remove JFR events that expose hashtable

[Erik Gahlin]

On Wed, 15 Oct 2025 08:30:03 GMT, Goetz Lindenmaier <goetz at openjdk.org> wrote:

> I backport this for parity with 17.0.18-oracle.
> 
> Resolved EventNames.java, probably clean anyways.

Sorry about this. Oracle plans to back out the removal of these events, as the enhancement backport was a mistake. Instead, the events will be disabled in default.jfc, which is much less intrusive but still prevents excessive overhead in the out-of-the-box configuration.

In other words, only make this change:


diff --git a/src/jdk.jfr/share/conf/jfr/default.jfc b/src/jdk.jfr/share/conf/jfr/default.jfc
index 6faba56991c..6b5659a24b0 100644
--- a/src/jdk.jfr/share/conf/jfr/default.jfc
+++ b/src/jdk.jfr/share/conf/jfr/default.jfc
@@ -38,17 +38,17 @@
     </event>
 
     <event name="jdk.PlaceholderTableStatistics">
-      <setting name="enabled">true</setting>
+      <setting name="enabled">false</setting>
       <setting name="period">10 s</setting>
     </event>
 
     <event name="jdk.LoaderConstraintsTableStatistics">
-      <setting name="enabled">true</setting>
+      <setting name="enabled">false</setting>
       <setting name="period">10 s</setting>
     </event>
 
     <event name="jdk.ProtectionDomainCacheTableStatistics">
-      <setting name="enabled">true</setting>
+      <setting name="enabled">false</setting>
       <setting name="period">10 s</setting>
     </event>

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

PR Comment: https://git.openjdk.org/jdk17u-dev/pull/4047#issuecomment-3408937611