This is boosting VirtualThread allocations while using https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/Thread.Builder.OfVirtual.html#name(java.lang.String,long)
The pattern has been discovered on https://github.com/quarkusio/quarkus/issues/51201 and narrowed down in https://github.com/franz1981/java-puzzles/commit/5cb4216e8d56cdc6c3c23629419158550cbd9068 which, on my machine (Ryzen 7950 w fixed frequency at 4.2 GHz): Benchmark Mode Cnt Score Error Units VarHandlePolymorphicSignatureSensitivity.rightVarHandle avgt 10 1.852 ± 0.007 ns/op VarHandlePolymorphicSignatureSensitivity.rightVarHandleConcatIndy avgt 10 9.891 ± 0.103 ns/op VarHandlePolymorphicSignatureSensitivity.wrongVarHandle avgt 10 10.430 ± 0.045 ns/op VarHandlePolymorphicSignatureSensitivity.wrongVarHandleConcatIndy avgt 10 19.312 ± 0.619 ns/op where the `right` indy shows: <img width="1915" height="469" alt="image" src="https://github.com/user-attachments/assets/4c836389-492b-4cc6-94a3-849f8cf6ea09"; /> vs the `wrong` one: <img width="1915" height="469" alt="image" src="https://github.com/user-attachments/assets/73765060-8e95-42a2-a03a-4f53f927a8b8"; /> ------------- Commit messages: - VarHandle wrongly uses int parameter on VirtualThread creation Changes: https://git.openjdk.org/jdk/pull/28475/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28475&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8372410 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/28475.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/28475/head:pull/28475 PR: https://git.openjdk.org/jdk/pull/28475
