The G1 Hot Card Cache has been removed. Performance testing has shown that after improvements to the concurrent refinement control, it does not contribute to performance.

Removal reduces the memory footprint of the G1 garbage collector by around 0.2% of the Java heap size.

The associated configuration options `G1ConcRSLogCacheSize` and `G1ConcRSHotCardLimit` have been obsoleted. A warning will be issued at startup about these options if they are used.