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

Vladimir Kozlov vladimir.kozlov at oracle.com
Tue Mar 20 22:23:00 UTC 2018


Actually you don't need to specify EliminateAutoBox in tests because it is true by default:

http://hg.openjdk.java.net/jdk/hs/file/74db2b7cec75/src/hotspot/share/opto/c2_globals.hpp#l506

Vladimir

On 3/20/18 3:20 PM, Vladimir Kozlov wrote:
> Hi Tobias,
> 
> EliminateAutoBox is C2 specific flag. Please, add -XX:+IgnoreUnrecognizedVMOptions flag in case 
> someone has VM without C2.
> 
> Thanks,
> Vladimir
> 
> On 3/20/18 2:20 AM, 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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