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  1. JDK
  2. JDK-8165292

The gc+task logging is repeated a lot, decreasing the usefulness of -Xlog:gc*=info

    Details

    • Type: Bug
    • Status: Closed
    • Priority: P2
    • Resolution: Fixed
    • Affects Version/s: 9
    • Fix Version/s: 9
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
      gc
    • Resolved In Build:
      b137
    • Verification:
      Verified

      Description

      The logging on gc,task is repeated a lot, see the following example:

      [24.798s][info][gc ] GC(14) Pause Young (G1 Evacuation Pause) 1349M->74M(4776M) (24.173s, 24.798s) 625.258ms
      [24.798s][info][gc,cpu ] GC(14) User=2.35s Sys=0.33s Real=0.63s
      [26.584s][info][gc,start ] GC(15) Pause Young (G1 Evacuation Pause) (26.584s)
      [26.584s][info][gc,task ] GC(15) GC Workers: using 18 out of 18
      [26.585s][info][gc,task ] GC(15) GC Workers: using 18 out of 18
      [26.632s][info][gc,task ] GC(15) GC Workers: using 18 out of 18
      [26.680s][info][gc,task ] GC(15) GC Workers: using 2 out of 18
      [26.680s][info][gc,task ] GC(15) GC Workers: using 18 out of 18
      [26.683s][info][gc,task ] GC(15) GC Workers: using 18 out of 18
      [26.683s][info][gc,task ] GC(15) GC Workers: using 18 out of 18
      [26.683s][info][gc,task ] GC(15) GC Workers: using 15 out of 18
      [26.866s][info][gc,task ] GC(15) GC Workers: using 18 out of 18

      This is because AbstractWorkGang::update_active_workers *always* logs on the tags gc and task on info level. How often is AbstractWorkGang::update_active_workers called? Twice for every time WorkGang::run_task is called, resulting a lot of additional logging.

      The bug is worse because a user can no longer enable the info level for all tags with gc by using -Xlog:gc*=info, since the output becomes too large.

      The bug is reproducible by running e.g. GCBasher with -Xlog:gc*=info.

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            • Assignee:
              tschatzl Thomas Schatzl
              Reporter:
              ehelin Erik Helin
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              • Created:
                Updated:
                Resolved: