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  1. JDK
  2. JDK-8176565

G1 Does not perform heap verification after remark with VerifyAfterGC

    Details

    • Type: Bug
    • Status: Open
    • Priority: P4
    • Resolution: Unresolved
    • Affects Version/s: 9
    • Fix Version/s: 10
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
      gc

      Description

      G1 Currently does not perform a verification of the heap at the end of a concurrent cycle. This leads to situations where the expectation that enabling VerifyBefore/AfterGC can be used to rule out GC implementation problems as a source to bugs is false.
      Since G1 is becoming the default GC in 9 I'd prefer to fix this in 9 to make it easier to debug GC problems in the field.
      Suggested fix is to add " || VerifyAfterGC" to the if statements in the end of G1ConcurrentMark::checkpointRootsFinal

        Activity

        Hide
        mgerdin Mikael Gerdin added a comment -
        9-critical-request-justification:
        This would have made investigation of JDK-8176365 and JDK-8176100 much clearer.
        For G1-as-default it would be good to have this in 9.0 to assist debugging issues in the field where there is a bunch of knowledge already about the VerifyBefore/AfterGC flags.
        The risk in adding this fix is considered low since it only adds one simple check for the verification flags.
        Show
        mgerdin Mikael Gerdin added a comment - 9-critical-request-justification: This would have made investigation of JDK-8176365 and JDK-8176100 much clearer. For G1-as-default it would be good to have this in 9.0 to assist debugging issues in the field where there is a bunch of knowledge already about the VerifyBefore/AfterGC flags. The risk in adding this fix is considered low since it only adds one simple check for the verification flags.

          People

          • Assignee:
            Unassigned
            Reporter:
            mgerdin Mikael Gerdin
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            Dates

            • Created:
              Updated: