RFR: 8218746: SA: Implement discontiguous bitmap for ZGC

[Stefan Karlsson]

On 2019-02-14 17:04, Jini George wrote:
> Hi Stefan,
>
> Looks good to me. Nit: Could you please modify the copyright year? And 
> don't we have to add the copyright message to the new file 
> ZExternalBitMap.java ?

Thanks. I've gone through all my SA patches and updated the copyright year.

StefanK
>
> Thanks!
> Jini.
>
> On 2/11/2019 7:25 PM, Stefan Karlsson wrote:
>> Hi all,
>>
>> Please review this patch to implement a discontiuous bitmap for ZGC 
>> in the SA.
>>
>> http://cr.openjdk.java.net/~stefank/8218746/webrev.01/
>> https://bugs.openjdk.java.net/browse/JDK-8218746
>>
>> ZGC uses a 16TB virtual memory address range, so the normal scheme to 
>> map a bitmap over the entire address range uses too much memory. This 
>> patch lazily creates smaller bitmaps per ZPage, when at() or atPut() 
>> is called.
>>
>> This patch builds upon JDK-8218743.
>>
>> Tested with serviceability/sa and manually running Reverse Object 
>> Analysis in the SA.
>>
>> Thanks,
>> StefanK