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  1. JDK
  2. JDK-8256675

Zero: purge biased locking support

    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P4
    • Resolution: Fixed
    • Affects Version/s: 8, 11, 15, 16
    • Fix Version/s: 16
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
    • Resolved In Build:
      b26

      Description

      Biased locking support was always disabled for C++ interpreter. Zero seems to have inherited that, see block in arguments.cpp:

      #ifdef ZERO
        // Clear flags not supported on zero.
        FLAG_SET_DEFAULT(ProfileInterpreter, false);
        FLAG_SET_DEFAULT(UseBiasedLocking, false);
        LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedOops, false));
        LP64_ONLY(FLAG_SET_DEFAULT(UseCompressedClassPointers, false));
      #endif // ZERO

      But zero/bytecodeInterpreter.cpp still has paths that imply biased locking support. Seeing that biased locking can go away, and the cost/benefit balance of supporting it in Zero, it makes more sense to purge the long-time-disabled biased locking support from Zero.

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              • Assignee:
                shade Aleksey Shipilev
                Reporter:
                shade Aleksey Shipilev
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                • Created:
                  Updated:
                  Resolved: