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  1. JDK
  2. JDK-8077945

Incorrect or inaccurate logging for G1 GC

    Details

    • Type: Bug
    • Status: Closed
    • Priority: P5
    • Resolution: Not an Issue
    • Affects Version/s: 8u40
    • Fix Version/s: 10
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
      gc
    • CPU:
      x86
    • OS:
      linux_2.6

      Description

      The suspicion is that G1 GC logging is partly incorrect and/or inaccurate
      The attached gc.log file contains the command line args at the top.

      1. Line 134:
         [Eden: 2456.0M(2456.0M)->0.0B(2200.0M) Survivors: 0.0B->256.0M Heap: 2456.0M(24.0G)->249.9M(24.0G)]

      The survivors contain 256.0m while the total heap contains 249.9m.
      This is inaccurate at best.

      2. Line 7500
         [Eden: 3568.0M(3568.0M)->0.0B(3216.0M) Survivors: 112.0M->464.0M Heap: 11.3G(24.0G)->8694.0M(24.0G)]

      My understanding is that eden is now 3216.0M. When looking at the subsequent
      collection at line 7652 the size of eden is now 1992m containing 2520m which means
      it's 127% full .This is clearly wrong :

         [Eden: 2520.0M(1992.0M)->0.0B(2144.0M) Survivors: 464.0M->312.0M Heap: 11.0G(24.0G)->10236.0M(24.0G)]


      If the eden was resized somewhere between the collections at 7500 and 7652 this should be logged.

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              • Assignee:
                Unassigned
                Reporter:
                tviessma Thomas Viessmann (Inactive)
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                • Created:
                  Updated:
                  Resolved: