PredictedClassLoadCount not working

[Alexandre Aisinzon]

Hi all

I read on page 15 of http://www.myexpospace.com/JavaOne2012/SessionFiles/CON7236_PDF_7236_0001.pdf that, by default, the system dictionary was sized at 1009.
Therefore, I tried to run "-XX:+UnlockExperimentalVMOptions -XX:PredictedClassLoadCount=#" with a value around 50,000.
The JVM does not seem to recognize the parameter.

Output of ./java -XX:+UnlockExperimentalVMOptions -XX:PredictedClassLoadCount=50000  -version is:

Unrecognized VM option 'PredictedClassLoadCount=50000'
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

I then ran with -verbose:class and counted that 46956 classes were allocated, which further justified the interest in sizing the system dictionary.

The test was conducted on JDK 1.7 u17 64 bit for Linux. Java -version output is:
java version "1.7.0_17"
Java(TM) SE Runtime Environment (build 1.7.0_17-b02)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)

Thanks for any pointers on this seemingly interesting parameter.

Alex Aisinzon

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