Is option "ShenandoahAllocationThreshold" still experimental in OpenJDK15 ?

[thevenet.fred at free.fr]

Hi, 

I've been using ShenandoahGC since the release of OpenJDK 13 (as provided by Azul[1]) to benefit from its " ShenandoahGCHeuristics=compact" option which is a good fit for my need (a generally small, non critical, client application with transient needs for a larger heap). 

More specifically, I use the following parameters: -XX: +UnlockExperimentalVMOptions -XX:+UseShenandoahGC -XX:ShenandoahGCHeuristics=compact -XX:ShenandoahAllocationThreshold=20 

Starting with 15, I was under the impression I no longer needed to set +UnlockExperimentalVMOptions, to use the above options. Yet starting a JVM with without unlocking experimental options yields the following error: "Error: VM option 'ShenandoahAllocationThreshold' is experimental and must be enabled via -XX:+UnlockExperimentalVMOptions." 

If I simply omit "ShenandoahAllocationThreshold", then the JVM starts. 

Is this the expected behaviour? If so, is there a list of Shenandoah- specific options that are still experimental somewhere? 

Thanks 

-- Fred. 


[1] https://www.azul.com/downloads/zulu-community/?architecture=x86-64-bit&package=jdk