RFR: 8209894: ZGC: Cap number of GC workers based on heap size

[Per Liden]

Thanks for reviewing, Erik and Thomas!

/Per

On 08/24/2018 03:02 PM, Thomas Schatzl wrote:
> Hi,
> 
> On Fri, 2018-08-24 at 14:36 +0200, Per Liden wrote:
>> Hi,
>>
>> Thanks for reviewing Erik. However, I reworked this a little bit.
>> Instead of using HeapSizePerGCThread, which has no real correlation
>> with the overhead per worker thread, I'm using a cap based on the
>> percent of the max heap size that we allow the reserve to occupied.
>> The end result is similar, i.e. we use a low number of threads on
>> tiny heaps.
>>
>> http://cr.openjdk.java.net/~pliden/8209894/webrev.1
> 
>    looks good to me.
> 
> Thomas
>