[11] RFR(S): 8199777: Deprecate -XX:+AggressiveOpts

David Holmes david.holmes at oracle.com
Wed Mar 21 02:46:55 UTC 2018

Hi Tobias,

The actual deprecation changes look fine.

Regarding the tests, I would not rely on the default for 
EliminateAutoBox. If the default were to change it would be impossible 
to know that these tests expect to test it being turned on. Arguably 
however the flags AggressiveOpts affected when the tests were created 
may be quite different to what is left now, so it may be the tests 
already don't really test what they originally intended to test. :(


On 20/03/2018 7:20 PM, Tobias Hartmann wrote:
> Hi,
> please review the following patch:
> https://bugs.openjdk.java.net/browse/JDK-8199777
> http://cr.openjdk.java.net/~thartmann/8199777/webrev.00/
> The VM option "-XX:+AggressiveOpts" should be deprecated in JDK 11 and removed in a future release.
> The option was originally supposed to enable some experimental optimizations of the C2 compiler to
> improve performance of specific benchmarks. Most features have been removed or integrated over time
> leaving the behavior of the option ill-defined and error-prone. The only effect that the flag
> currently has is setting "AutoBoxCacheMax" to 20000 and "BiasedLockingStartupDelay" to 500. The same
> configuration can be achieved by setting the corresponding flags via the command line.
> I've deprecated the flag and replaced the usages in tests by -XX:+EliminateAutoBox
> -XX:AutoBoxCacheMax=20000.
> Thanks,
> Tobias

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