Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8306768

CodeCache Analytics reports wrong threshold

    XMLWordPrintable

Details

    • b01
    • generic
    • generic

    Backports

      Description

        https://github.com/openjdk/jdk17u-dev/blob/f969f811a71603f39e4ab42f1362271b7a4d303d/src/hotspot/share/code/codeHeapState.cpp#L1155

        Jcmd CodeCache_Analytics uses own implementation of threshold calculation, allowing an error to creep in, making report invalid. Instead of unallocated size, it uses uncommitted size. The problem especially visialbe with InitialCodeCacheSize == ReservedCodeCacheSize.

        https://github.com/openjdk/jdk17u-dev/blob/f969f811a71603f39e4ab42f1362271b7a4d303d/src/hotspot/share/code/codeCache.cpp#L926

        {code}
        java -XX:InitialCodeCacheSize=1G -XX:ReservedCodeCacheSize=1G Sleep.java

        jcmd jdk.compiler/com.sun.tools.javac.launcher.Main Compiler.CodeHeap_Analytics | grep -A 2 "Threshold for method to be considered 'cold'"
        Threshold for method to be considered 'cold': 5330737152.000
        min. hotness = 1016
        avg. hotness = 2048
        --
        Threshold for method to be considered 'cold': 5330696192.000
        min. hotness = 1016
        avg. hotness = 2048
        --
        Threshold for method to be considered 'cold': 75978752.000
        No hotness data available
        {code}

        Attachments

          Issue Links

            backported by

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8307001 CodeCache Analytics reports wrong threshold

            • P5 - Cosmetic problem like misspelt words or misaligned text.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8307003 CodeCache Analytics reports wrong threshold

            • P5 - Cosmetic problem like misspelt words or misaligned text.
            • Resolved

            Backport - A issue that is required to port a Bug or Feature into another product release. This issue type is generally associated with the main Bug/Feature to represent each individual release of the port. JDK-8307061 CodeCache Analytics reports wrong threshold

            • P5 - Cosmetic problem like misspelt words or misaligned text.
            • Resolved
            relates to

            Enhancement - null JDK-8198691 CodeHeap State Analytics

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved

            Enhancement - null JDK-8290025 Remove the Sweeper

            • P4 - Minor loss of function, or other problem where easy workaround is present.
            • Resolved
            links to

            Commit Commit openjdk/jdk11u-dev/42ae833f

            Commit Commit openjdk/jdk17u-dev/243e6430

            Review Review openjdk/jdk11u-dev/1849

            Review Review openjdk/jdk17u-dev/1295

            Activity

              People

                akozlov Anton Kozlov
                akozlov Anton Kozlov
                Votes:
                0 Vote for this issue
                Watchers:
                5 Start watching this issue

                Dates

                  Created:
                  Updated:
                  Resolved: