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  1. JDK
  2. JDK-8065402

G1 does not expand marking stack when mark stack overflow happens during concurrent marking

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 9
    • Fix Version/s: 10
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
      gc
    • Resolved In Build:
      b21
    • CPU:
      generic
    • OS:
      generic

      Description

      Attached is the spreadsheet summarizing Intel's experiment increasing MarkStackSize manually vs count of
      '[GC concurrent-mark-reset-for-overflow]'

      The observation is we do not expand MarkStackSize to MarkStackSizeMax when concurrent-mark-overflow happens. They have to increase it manually.

      The expand flag is set when concurrent-mark-reset-for-overflow happens.
      The issue is we try to expand markStack in void ConcurrentMark::checkpointRootsFinal(bool clear_all_soft_refs)
      If there is no overflow, at the end, we call set_non_marking_state(); then try to expand markStack.

      set_non_marking_state() calls reset_marking_state and reset expand based on _cm->has_overflown(_cm overflow is cleaned during marking). So when we check if (_markStack.should_expand()), it is always false.

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              • Assignee:
                aharlap Alexander Harlap (Inactive)
                Reporter:
                yuzhang Jenny Zhang (Inactive)
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                • Created:
                  Updated:
                  Resolved: