RFR: 8218743: SA: Add support for large bitmaps

[Stefan Karlsson]

Thanks, Erik.

Stefank

On 2019-02-14 10:11, Erik Österlund wrote:
> Hi Stefan,
> 
> Looks good.
> 
> Thanks,
> /Erik
> 
> On 2019-02-11 13:36, Stefan Karlsson wrote:
>> Hi all,
>>
>> Please review this patch to add support for large bitmaps in the SA.
>>
>> http://cr.openjdk.java.net/~stefank/8218743/webrev.01/
>> https://bugs.openjdk.java.net/browse/JDK-8218743
>>
>> I've added a minimal interface (at, atPut, clear) that uses longs 
>> instead of ints, and changed MarkBits to use this interface.
>>
>> I've implemented a segmented bitmap that, currently, all GCs use when 
>> asked for a bitmap in MarkBits. Later ZGC will provide its own 
>> discontiguous bitmap, implementing the new interface, but that will be 
>> sent out as a separate RFE.
>>
>> I've tested this with a temporary patch that lowers the segment size 
>> and implements a jtreg test:
>> http://cr.openjdk.java.net/~stefank/8218743/webrev.test.01
>>
>> I ran through the all the tests in serviceability/sa with both these 
>> patches.
>>
>> Thanks,
>> StefanK