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  1. JDK
  2. JDK-8180175

ObjectSynchronizer only needs to iterate in-use monitors

    Details

    • Type: Enhancement
    • Status: Resolved
    • Priority: P3
    • Resolution: Fixed
    • Affects Version/s: 9, 10
    • Fix Version/s: 10
    • Component/s: hotspot
    • Labels:
    • Subcomponent:
    • Resolved In Build:
      master
    • CPU:
      generic
    • OS:
      generic

      Description

      ObjectSynchronizer::oops_do() currently iterates all monitor blocks, even free ones. With -XX:+MonitorInUseLists, each thread has its own in-use monitors list, and ObjectSynchronizer has a global gOmInUseList for moribund threads. Iterating over in-use monitors only significantly inmproves scanning time for monitors, because it avoids scanning free blocks, improves caching (no padding, and better chances to have thread-local oops in cache already).

        Issue Links

          Activity

          Hide
          hgupdate HG Updates added a comment -
          URL: http://hg.openjdk.java.net/jdk10/hs/hotspot/rev/85736adb8318
          User: dholmes
          Date: 2017-05-18 01:36:42 +0000
          Show
          hgupdate HG Updates added a comment - URL: http://hg.openjdk.java.net/jdk10/hs/hotspot/rev/85736adb8318 User: dholmes Date: 2017-05-18 01:36:42 +0000
          Hide
          hgupdate HG Updates added a comment -
          URL: http://hg.openjdk.java.net/jdk10/jdk10/hotspot/rev/85736adb8318
          User: jwilhelm
          Date: 2017-08-18 18:01:35 +0000
          Show
          hgupdate HG Updates added a comment - URL: http://hg.openjdk.java.net/jdk10/jdk10/hotspot/rev/85736adb8318 User: jwilhelm Date: 2017-08-18 18:01:35 +0000

            People

            • Assignee:
              rkennke Roman Kennke
              Reporter:
              rkennke Roman Kennke
            • Votes:
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              Dates

              • Created:
                Updated:
                Resolved: