RFR: 8218746: SA: Implement discontiguous bitmap for ZGC

Stefan Karlsson stefan.karlsson at oracle.com
Mon Feb 11 13:55:15 UTC 2019

Hi all,

Please review this patch to implement a discontiuous bitmap for ZGC in 
the SA.


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 

This patch builds upon JDK-8218743.

Tested with serviceability/sa and manually running Reverse Object 
Analysis in the SA.


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