Is option "ShenandoahAllocationThreshold" still experimental in OpenJDK15 ?

[Frederic Thevenet]

On 16/09/2020 18:36, Holger Hoffstätte wrote:
> On 2020-09-16 18:13, thevenet.fred at free.fr wrote:
>> 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
>
> Where did you find my options? :D
>
>> 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?
>
> I don't think it's the expected behaviour (as of 15) and can confirm that
> I get the same with the AdoptOpenJDK 15 binary that I'm currently 
> testing,
> so it's probably just an oversight/bug when parsing the arguments and
> checking their status. AFAIK there is nothing experimental about the
> ShenandoahAllocationThreshold flag itself or compact mode.
>
> cheers
> Holger

Thanks, that's what I suspected as well.

Should I open an issue somewhere? Btw, are Shenandoah issues tracked in 
the JBS? or somewhere else? Thanks.

-- Fred