RFR: 8354572: Turn off AlwaysMergeDMB for Ampere CPU by default

Tue Apr 15 12:06:46 UTC 2025

On Tue, 15 Apr 2025 09:56:41 GMT, Liming Liu <lliu at openjdk.org> wrote:

> > Please post the numbers here.
> 
> Hi @theRealAph, I ran the benchmark from [JDK-8354572](https://bugs.openjdk.org/browse/JDK-8354572) with `-UseStoreStoreForCtor`, and the thoughput is ~51.1k ops/ms for `-AlwaysMergeDMB` on Ampere1, while it is ~23.8k ops/ms for `+AlwaysMergeDMB`.

OK, I think I understand now. However, have there been any other tests to ensure that we don't see regressions elsewhere?

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PR Comment: https://git.openjdk.org/jdk/pull/24652#issuecomment-2804817919