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  1. JDK
  2. JDK-8056240

Investigate increased GC remark time after class unloading changes in CRM Fuse

    Details

    • Type: Bug
    • Status: Closed
    • Priority: P2
    • Resolution: Fixed
    • Affects Version/s: 8u40, 9
    • Fix Version/s: 9
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
      gc
    • Resolved In Build:
      b38
    • Verification:
      Not verified

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        Description

        Tests on CRM Fuse after Class Unloading after a concurrent marking cycle (JDK-8049421) had been pushed to the 8u40-dev show increased GC remark times that are larger than expected compared to earlier prototypes.

        E.g. log messages with -XX:G1LogLevel=finest show:
        13160.468: #4064: [GC remark
          13160.468: #4064: [Finalize Marking, 0.0013290 secs]
          13160.469: #4064: [GC ref-proc
            13160.469: #4064: [SoftReference, 4610 refs, 0.0022800 secs]
            13160.472: #4064: [WeakReference, 67021 refs, 0.0236090 secs]
            13160.495: #4064: [FinalReference, 1279 refs, 0.0056960 secs]
            13160.501: #4064: [PhantomReference, 38 refs, 0.0000850 secs]
            13160.501: #4064: [JNI Weak Reference, 0.0000120 secs],
          0.0325860 secs]
        13160.502: #4064: [Unloading
           13160.502: #4064: [System Dictionary Unloading, 0.2235080 secs]
          13160.725: #4064: [Parallel Unloading, 0.0444030 secs],
          0.2679750 secs],
        0.3044090 secs]

        Particularly the System Dictionary Unloading times look too high. Investigate the cause and eventually look for fixes.

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                • Assignee:
                  stefank Stefan Karlsson
                  Reporter:
                  tschatzl Thomas Schatzl
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                  • Created:
                    Updated:
                    Resolved: