RFR (M): 8233919: Incrementally calculate the occupied cards in a heap region remembered set
thomas.schatzl at oracle.com
Tue Nov 12 15:24:13 UTC 2019
may I have reviews for this change that ultimately makes sure that
the number of occupied cards in a remembered set is only growing by
providing a per-OtherRegionsTable count that is atomically updated when
adding a remembered set entry.
Note that this count may not be completely accurate due to races when
deleting a PerRegionTable (which is a known issue) from an
OtherRegionsTable; but that is no different than before.
This helps improving the predictions in the young gen remset sampling
thread, and increase the performance of getting the occupancy count.
Based on JDK-8233997, and JDK-8233998 also out for review.
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