RFR: 8232001: ZGC: Ignore metaspace GC threshold until GC is warm

[Per Liden]

Thanks Erik!

/Per

On 10/16/19 9:01 AM, Erik Osterlund wrote:
> Hi Per,
> 
> Looks good.
> 
> /Erik
> 
>> On 8 Oct 2019, at 15:03, Per Liden <per.liden at oracle.com> wrote:
>>
>> As reported here:
>>
>> https://mail.openjdk.java.net/pipermail/zgc-dev/2019-September/000736.html
>>
>> The ZDirector heuristics can get of to a bad start if the statistics is contaminated by early "Metaspace GC Threshold" GC requests. To avoid this, we could simply ignore such requests until the GC is warm, at the potential cost of expanding metaspace a bit more during startup.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8232001
>> Webrev: http://cr.openjdk.java.net/~pliden/8232001/webrev.0
>>
>> /Per
>