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  1. JDK
  2. JDK-8253600

G1: Fully support pinned regions for full gc

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    • gc
    • b24

    Description

      After full gc all PTAMS of all regions are set to the bottom of the region.
      There is some special handling for humongous regions where instead of setting ptams correctly, g1 simply clears the mark of the humongous object (and keeps ptams at the bottom)

      Use of G1VerifyBitmaps also clears all prev bitmaps.

      This is wrong for "real" pinned regions with multiple live and dead objects inside - their ptams and bitmap below ptams must be preserved.

      Since currently g1 does not support such kind of pinned regions and there is no problem, this has been filed as an enhancement.

      However one potential solution for JDK-8253081 involves making the old archive regions regular (pinned, due to COW) regions.

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          blocks

          Bug - A problem which impairs or prevents the functions of the product. JDK-8253081 G1 fails on stale objects in archived module graph in Open Archive regions

          • P3 - Major loss of function.
          • Resolved
          is blocked by

          Bug - A problem which impairs or prevents the functions of the product. JDK-8254695 G1: Next mark bitmap clear not cancelled after marking abort

          • P5 - Cosmetic problem like misspelt words or misaligned text.
          • Resolved

          Enhancement - null JDK-8255232 G1: Make G1BiasedMappedArray freeable

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved
          relates to

          Enhancement - null JDK-8236594 G1: Provide object pinning

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Open

          Enhancement - null JDK-8264423 G1: Rename full gc attribute table states

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          JEP - Java Enhancement Proposal JDK-8276094 JEP 423: Region Pinning for G1

          • P4 - Minor loss of function, or other problem where easy workaround is present.
          • Candidate
          links to

          Commit Commit openjdk/jdk/6555996f

          Review Review openjdk/jdk/824

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              tschatzl Thomas Schatzl
              tschatzl Thomas Schatzl
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                Updated:
                Resolved: