Not able to turn off G1 GC in JDK-9 preview builds?

[Attila-Mihaly Balazs]

Hello,

I'm trying to do some benchmarks and was curious what effect using / not
using G1 GC had on it. However I'm unable to turn it off in the latest
JDK-9 beta build (111):

~/jdk-9-111/bin/java -XX:-UseG1GC -XX:+PrintFlagsFinal -version | grep
UseG1GC
     bool UseG1GC                                  :=
true                                {product}
java version "9-ea"
Java(TM) SE Runtime Environment (build 9-ea+111)
Java HotSpot(TM) 64-Bit Server VM (build 9-ea+111, mixed mode)

With JDK-8 this works as expected:

~/jdk1.8.0_72/bin/java -XX:-UseG1GC -XX:+PrintFlagsFinal -version | grep
UseG1GC
     bool UseG1GC                                  :=
false                               {product}
java version "1.8.0_72"
Java(TM) SE Runtime Environment (build 1.8.0_72-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.72-b15, mixed mode)

Any pointers as to what my be the issue? I understand that there is a push
to use G1 GC by default in Java 9, however it was my understanding that the
previous GC algorithms will still be available.

Thank you,
Attila Balazs