G1: Missing post barrier in processing of j.l.ref.Reference objects

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    • Type: Bug
    • Resolution: Fixed
    • Priority: P2
    • 9
    • Affects Version/s: 8u20, 9
    • Component/s: hotspot
    • gc
    • b19
    • Not verified

        The fix for JDK-8029255 removed the post barrier for setting the next field of Reference objects.

        http://hg.openjdk.java.net/jdk9/hs-gc/hotspot/rev/fbc1677398c0

        That post barrier dirtied a lot of cards that didn't really have to be dirty, but it saved us from other missed card marks. See for example JDK-8031703.

        When running the Stress BPM another case of a missing barrier was detected.

        The missing barrier occurs when we prune the discovered list in G1 and the list contains reference objects that are in different old regions.

              Assignee:
              Bengt Rutisson (Inactive)
              Reporter:
              Bengt Rutisson (Inactive)
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                Created:
                Updated:
                Resolved: