Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8243615

C2: Continuous deoptimizations with Reason=unstable_if and Action=none

    Details

    • Subcomponent:
    • CPU:
      generic
    • OS:
      generic

      Description

      Continuous deoptimization w/ Reason_unstable_if and Action_none happeded in an online application and significant performance drop was observed.
      It seems this bug is triggered when
      1. Too many deoptimizations happened in a method.
      2. In the last recompilation, Reason_unstable_if Action_reinterpret uncommon traps were changed to Reason_unstable_if Action_none.
      3. The uncommon traps were executed but this method never recompiled.

      To reproduce:
      javac DeoptimizationTest.java
      java -XX:PerMethodRecompilationCutoff=4 DeoptimizationTest
      PerMethodRecompilationCutoff is used to make it easier to reproduce and is not used in the above online application.

        Attachments

          Activity

            People

            • Assignee:
              wzhuo Wang Zhuo
              Reporter:
              wzhuo Wang Zhuo
            • Votes:
              0 Vote for this issue
              Watchers:
              5 Start watching this issue

              Dates

              • Created:
                Updated: